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Event: core_pattern_access

Quick Explanation

The core_pattern_access recipe detects changes to the system's core dump pattern configuration file. This file is vital for managing core dumps, which are essential for debugging and forensic analysis. Unauthorized changes to this file can redirect or manipulate core dumps to evade detection or conceal malicious activities. Such modifications can prevent the capture of accurate system state information during crashes, potentially caused by exploits.

More Information

Information

  1. Description: Core pattern config file access
  2. Category: Defense Evasion
  3. Method: Impair Defenses
  4. Importance: Critical

Analysis of the Event

The core_pattern_access detection event is triggered by attempts to modify the system's core dump pattern, typically found at /proc/sys/kernel/core_pattern. This file dictates how core dumps are managed by the kernel, including their formatting and output destination, which is crucial for debugging and forensic analysis. Malicious changes to this file could redirect or manipulate core dumps to evade detection or obscure malicious activity, aligning with the MITRE ATT&CK framework's tactics for defense evasion and impairment of defensive measures.

The implications of such modifications are significant, as they can prevent system administrators and security tools from obtaining accurate information about the system's state during a crash, potentially induced by an exploit or other malicious activities. By altering core dump handling, attackers could remove traces of their presence or activity from being captured in these dumps.

Implications for the CI/CD Pipeline

Detecting an attempt to modify /proc/sys/kernel/core_pattern during a CI/CD pipeline execution suggests that recent code changes might introduce vulnerabilities or backdoors intended to manipulate system behavior during error handling. If such changes were merged into production, it could lead to compromised systems where forensic data is unreliable or misleading, significantly hampering incident response and recovery efforts in a live environment.

To mitigate risks associated with this detection:

  1. Review Recent Commits: Examine changes in recent commits related to system configuration files or scripts interacting with /proc/sys/kernel/core_pattern. Look for unauthorized or unusual modifications.
  2. Audit Access Controls: Ensure that only authorized personnel and systems have write access to critical system files like /proc/sys/kernel/core_pattern. Implement strict access controls based on roles.
  3. Enhance Monitoring: Increase monitoring around access and modification of critical system files. Utilize file integrity monitoring tools that can alert on unauthorized changes to sensitive files.
  4. Conduct Code Analysis: Perform static code analysis on updates affecting system configurations or scripts capable of modifying them. Look for potentially malicious code snippets that could alter operational characteristics.
  5. Educate Developers: Provide training for developers on secure coding practices, especially related to system configuration and error handling mechanisms.
  6. Validate with Security Teams: Before merging any changes affecting system configurations, have your security team thoroughly review these alterations.

By following these steps, you can help safeguard your infrastructure against attempts to evade defenses through manipulation of core dump configurations in both development and production environments.