Free CISSP Questions Attempt

 Implementing logical network segmentation at the switches is the most effective layer of security the organization could have implemented to mitigate the attacker’s ability to gain further information. Logical network segmentation is the process of dividing a network into smaller subnetworks or segments based on criteria such as function, location, or security level. Logical network segmentation can be implemented at the switches, which are devices that operate at the data link layer of the OSI model and forward data packets based on the MAC addresses. Logical network segmentation can provide several benefits, such as:

• Isolating network traffic and reducing congestion and collisions
• Enhancing performance and efficiency of the network
• Improving security and confidentiality of the network
• Restricting the scope and impact of attacks
• Enforcing access control and security policies
• Facilitating monitoring and auditing of the network

Logical network segmentation can mitigate the attacker’s ability to gain further information by limiting the visibility and access of the sniffer to the segment where it is installed. A sniffer is a tool that captures and analyzes the data packets that are transmitted over a network. A sniffer can be used for legitimate purposes, such as troubleshooting, testing, or monitoring the network, or for malicious purposes, such as eavesdropping, stealing, or modifying the data. A sniffer can only capture the data packets that are within its broadcast domain, which is the set of devices that can communicate with each other without a router. By implementing logical network segmentation at the switches, the organization can create multiple broadcast domains and isolate the sensitive or critical data from the compromised segment. This way, the attacker can only see the data packets that belong to the same segment as the sniffer, and not the data packets that belong to other segments. This can prevent the attacker from gaining further information or accessing other resources on the network.

The other options are not the most effective layers of security the organization could have implemented to mitigate the attacker’s ability to gain further information, but rather layers that have other limitations or drawbacks. Implementing packet filtering on the network firewalls is not the most effective layer of security, because packet filtering only examines the network layer header of the data packets, such as the source and destination IP addresses, and does not inspect the payload or the content of the data. Packet filtering can also be bypassed by using techniques such as IP spoofing or fragmentation. Installing Host Based Intrusion Detection Systems (HIDS) is not the most effective layer of security, because HIDS only monitors and detects the activities and events on a single host, and does not prevent or respond to the attacks. HIDS can also be disabled or evaded by the attacker if the host is compromised. Requiring strong authentication for administrators is not the most effective layer of security, because authentication only verifies the identity of the users or processes, and does not protect the data in transit or at rest. Authentication can also be defeated by using techniques such as phishing, keylogging, or credential theft.

WEP uses a small range Initialization Vector (IV) is the factor that contributes to the weakness of Wired Equivalent Privacy (WEP) protocol. WEP is a security protocol that provides encryption and authentication for wireless networks, such as Wi-Fi. WEP uses the RC4 stream cipher to encrypt the data packets, and the CRC-32 checksum to verify the data integrity. WEP also uses a shared secret key, which is concatenated with a 24-bit Initialization Vector (IV), to generate the keystream for the RC4 encryption. WEP has several weaknesses and vulnerabilities, such as:

• WEP uses a small range Initialization Vector (IV), which results in 16,777,216 (2^24) possible values. This might seem large, but it is not enough for a high-volume wireless network, where the same IV can be reused frequently, creating keystream reuse and collisions. An attacker can capture and analyze the encrypted data packets that use the same IV, and recover the keystream and the secret key, using techniques such as the Fluhrer, Mantin, and Shamir (FMS) attack, or the KoreK attack.
• WEP uses a weak integrity check, which is the CRC-32 checksum. The CRC-32 checksum is a linear function that can be easily computed and manipulated by anyone who knows the keystream. An attacker can modify the encrypted data packets and the checksum, without being detected, using techniques such as the bit-flipping attack, or the chop-chop attack.
• WEP uses a static and shared secret key, which is manually configured and distributed among all the wireless devices that use the same network. The secret key is not changed or refreshed automatically, unless the administrator does it manually. This means that the secret key can be exposed or compromised over time, and that all the wireless devices can be affected by a single key breach. An attacker can also exploit the weak authentication mechanism of WEP, which is based on the secret key, and gain unauthorized access to the network, using techniques such as the authentication spoofing attack, or the shared key authentication attack.

WEP has been deprecated and replaced by more secure protocols, such as Wi-Fi Protected Access (WPA) or Wi-Fi Protected Access II (WPA2), which use stronger encryption and authentication methods, such as the Temporal Key Integrity Protocol (TKIP), the Advanced Encryption Standard (AES), or the Extensible Authentication Protocol (EAP).

The other options are not factors that contribute to the weakness of WEP, but rather factors that are irrelevant or incorrect. WEP does not use Message Digest 5 (MD5), which is a hash function that produces a 128-bit output from a variable-length input. WEP does not use Diffie-Hellman, which is a method for generating a shared secret key between two parties. WEP does use an Initialization Vector (IV), which is a 24-bit value that is concatenated with the secret key.

 Making a copy of the hard drive should be the first action to protect the chain of evidence when a desktop computer is involved. A chain of evidence, also known as a chain of custody, is a process that documents and preserves the integrity and authenticity of the evidence collected from a crime scene, such as a desktop computer. A chain of evidence should include information such as:

• The identity and role of the person who collected, handled, or transferred the evidence
• The date and time of the collection, handling, or transfer of the evidence
• The location and condition of the evidence
• The method and tool used to collect, handle, or transfer the evidence
• The signature or seal of the person who collected, handled, or transferred the evidence

Making a copy of the hard drive should be the first action to protect the chain of evidence when a desktop computer is involved, because it can ensure that the original hard drive is not altered, damaged, or destroyed during the forensic analysis, and that the copy can be used as a reliable and admissible source of evidence. Making a copy of the hard drive should also involve using a write blocker, which is a device or a software that prevents any modification or deletion of the data on the hard drive, and generating a hash value, which is a unique and fixed identifier that can verify the integrity and consistency of the data on the hard drive.

The other options are not the first actions to protect the chain of evidence when a desktop computer is involved, but rather actions that should be done after or along with making a copy of the hard drive. Taking the computer to a forensic lab is an action that should be done after making a copy of the hard drive, because it can ensure that the computer is transported and stored in a secure and controlled environment, and that the forensic analysis is conducted by qualified and authorized personnel. Starting documenting is an action that should be done along with making a copy of the hard drive, because it can ensure that the chain of evidence is maintained and recorded throughout the forensic process, and that the evidence can be traced and verified. Turning off the computer is an action that should be done after making a copy of the hard drive, because it can ensure that the computer is powered down and disconnected from any network or device, and that the computer is protected from any further damage or tampering.

 Investigating all symptoms to confirm the incident is the first step in the incident response process. An incident is an event that violates or threatens the security, availability, integrity, or confidentiality of the IT systems or data. An incident response is a process that involves detecting, analyzing, containing, eradicating, recovering, and learning from an incident, using various methods and tools. An incident response can provide several benefits, such as:

• Improving the security and risk management of the IT systems and data by identifying and addressing the security weaknesses and gaps
• Enhancing the security and decision making of the IT systems and data by providing the evidence and information for the security analysis, evaluation, and reporting
• Increasing the security and improvement of the IT systems and data by providing the feedback and input for the security response, remediation, and optimization
• Facilitating the compliance and alignment of the IT systems and data with the internal or external requirements and standards

Investigating all symptoms to confirm the incident is the first step in the incident response process, because it can ensure that the incident is verified and validated, and that the incident response is initiated and escalated. A symptom is a sign or an indication that an incident may have occurred or is occurring, such as an alert, a log, or a report. Investigating all symptoms to confirm the incident involves collecting and analyzing the relevant data and information from various sources, such as the IT systems, the network, the users, or the external parties, and determining whether an incident has actually happened or is happening, and how serious or urgent it is. Investigating all symptoms to confirm the incident can also help to:

• Prevent the false positives or negatives that might cause the incident response to be delayed or unnecessary
• Identify the scope and impact of the incident on the IT systems and data
• Notify and inform the appropriate stakeholders and authorities about the incident
• Activate and coordinate the incident response team and resources

The other options are not the first steps in the incident response process, but rather steps that should be done after or along with investigating all symptoms to confirm the incident. Determining the cause of the incident is a step that should be done after investigating all symptoms to confirm the incident, because it can ensure that the root cause and source of the incident are identified and analyzed, and that the incident response is directed and focused. Determining the cause of the incident involves examining and testing the affected IT systems and data, and tracing and tracking the origin and path of the incident, using various techniques and tools, such as forensics, malware analysis, or reverse engineering. Determining the cause of the incident can also help to:

• Understand the nature and behavior of the incident and the attacker
• Detect and resolve any issues or risks caused by the incident
• Prevent and mitigate any future incidents or attacks involving the same or similar cause
• Support and enable the legal or regulatory actions or investigations against the incident or the attacker

Disconnecting the system involved from the network is a step that should be done along with investigating all symptoms to confirm the incident, because it can ensure that the system is isolated and protected from any external or internal influences or interferences, and that the incident response is conducted in a safe and controlled environment. Disconnecting the system involved from the network can also help to:

• Prevent the incident from communicating or connecting with any other system or network, and potentially spreading or escalating the attack
• Prevent the incident from receiving or sending any commands or data, and potentially altering or deleting the evidence
• Prevent the incident from detecting or evading the incident response, and potentially hiding or destroying itself

Isolating and containing the system involved is a step that should be done after investigating all symptoms to confirm the incident, because it can ensure that the incident is confined and restricted, and that the incident response is continued and maintained. Isolating and containing the system involved involves applying and enforcing the appropriate security measures and controls to limit or stop the activity and impact of the incident on the IT systems and data, such as firewall rules, access policies, or encryption keys. Isolating and containing the system involved can also help to:

• Minimize the damage and loss caused by the incident on the IT systems and data
• Maximize the recovery and restoration of the IT systems and data
• Support and enable the eradication and removal of the incident from the IT systems and data
• Facilitate the learning and improvement of the IT systems and data from the incident