Question 21 - PT0-003 discussion

During a penetration test, one of the critical steps for maintaining access and covering tracks is to clear evidence of the attack. Manipulating data to hide activities on an internal server involves ensuring that logs and traces of the attack are removed. Here's a detailed explanation of why clearing the Windows event logs is the best method for this scenario:

Understanding Windows Event Logs: Windows event logs are a key forensic artifact that records system, security, and application events. These logs can provide detailed information about user activities, system changes, and potential security incidents.

Why Clear Windows Event Logs:

Comprehensive Coverage: Clearing the event logs removes all recorded events, including login attempts, application errors, and security alerts. This makes it difficult for an investigator to trace back the actions performed by the attacker.

Avoiding Detection: Penetration testers clear event logs to ensure that their presence and activities are not detected by system administrators or security monitoring tools.

Method to Clear Event Logs:

Use the built-in Windows command line utility wevtutil to clear logs. For example:

shell

Copy code

wevtutil cl System

wevtutil cl Security

wevtutil cl Application

These commands clear the System, Security, and Application logs, respectively.

Alternative Options and Their Drawbacks:

Modify the System Time: Changing the system time can create confusion but is easily detectable and can be reverted. It does not erase existing log entries.

Alter Log Permissions: Changing permissions might prevent new entries but does not remove existing ones and can alert administrators to suspicious activity.

Reduce Log Retention Settings: This can limit future logs but does not affect already recorded logs and can be easily noticed by administrators.

Case

Reference:

HTB Writeups: Many Hack The Box (HTB) writeups demonstrate the importance of clearing logs post-exploitation to maintain stealth. For example, in the 'Gobox' and 'Writeup' machines, maintaining a low profile involved managing log data to avoid detection.

Real-World Scenarios: In real-world penetration tests, attackers often clear logs to avoid detection by forensic investigators and incident response teams. This step is crucial during red team engagements and advanced persistent threat (APT) simulations.

In conclusion, clearing Windows event logs is a well-established practice for hiding activities during a penetration test. It is the most effective way to remove evidence of the attack from the system, thereby maintaining stealth and ensuring that the tester's actions remain undetected.