Determining Network Incidents

B.

When a security analyst is investigating a potential network incident, they need to collect as much information as possible to determine the cause of the incident and its scope. The information gathered helps the analyst to identify the source of the incident, the extent of the damage caused, and the actions necessary to prevent a recurrence. Among the types of evidence the analyst can obtain, four options are given: volatile memory capture, traffic and logs, screenshots, and system image capture.

A. Volatile memory capture: This option refers to the collection of information stored in a computer's RAM, which is considered volatile because its contents are lost when the computer is shut down or restarted. The analyst can use specialized software tools to extract data from volatile memory, such as running processes, open files, network connections, and system configurations. Volatile memory capture is useful for detecting and analyzing malware, rootkits, and other types of malicious software that reside in memory and hide from traditional antivirus programs. The analyst can use the captured data to identify the malware's behavior, its persistence mechanisms, and the affected systems. Volatile memory capture is also useful for collecting evidence of user activity, such as passwords, keystrokes, and browser history, which can be used in forensic investigations.

B. Traffic and logs: This option refers to the collection of network traffic data and system logs generated by devices such as firewalls, routers, servers, and endpoints. Traffic data includes information about the source and destination IP addresses, port numbers, protocols, packet sizes, and timestamps of network packets flowing between devices. System logs include records of system events, such as login attempts, file access, software installation, and system errors. The analyst can use traffic and logs to reconstruct the timeline of the incident, trace the path of the attacker, and identify the entry point and the type of attack used. Traffic and logs can also reveal patterns of abnormal behavior, such as high network traffic, repeated login failures, and unusual file access, which can indicate an ongoing attack or a compromised system.

C. Screenshots: This option refers to the capture of images of the computer screen or application interface at a specific time. Screenshots can provide visual evidence of the state of the system or the user's activity when the incident occurred. The analyst can use screenshots to verify the presence of malware, identify the user's actions, or capture error messages or other relevant information that may not be available in logs or volatile memory. Screenshots can also be used to document the incident and provide visual aids for reports or presentations. However, screenshots alone may not provide enough context or detail to fully understand the incident.

D. System image capture: This option refers to the creation of a bit-for-bit copy of a computer's hard drive or system partition. A system image capture includes all files, directories, applications, and system settings stored on the target drive, as well as any hidden or deleted files. The analyst can use the system image to analyze the system offline, without risking further damage or alteration to the original system. System image capture is useful for identifying and removing malware, restoring a compromised system to a known good state, or recovering data that may have been deleted or encrypted. However, system image capture can be time-consuming and resource-intensive, and may require specialized equipment or software.

In conclusion, the most likely evidence that a security analyst would obtain to determine a network incident depends on the type of incident and the goals of the investigation. Volatile memory capture and traffic and logs are likely to be the most useful evidence types in most cases, as they provide real-time and historical data about the system and network activity. Screenshots and system image capture can provide additional context and detail, but may not be necessary or practical in all situations.