Details

Monitor the use of system calls associated with the deletion or renaming of files and file attributes. This configuration statement sets up monitoring for the unlink (remove a file), unlinkat (remove a file attribute), rename (rename a file) and renameat (rename a file attribute) system calls and tags them with the identifier ‘delete’. Monitoring these calls from non-privileged users could provide a system administrator with evidence that inappropriate removal of files and file attributes associated with protected files is occurring. While this audit option will look at all events, system administrators will want to look for specific privileged files that are being deleted or altered.

NOTE: This check only applies to 64 bit systems.

Solution

For 32 bit systems add the following lines to the /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S unlink -S unlinkat -S rename -S renameat -F auid>=500 -F auid!=4294967295 -k delete

For 64 bit systems add the following lines to the /etc/audit/audit.rules file:
-a always,exit -F arch=b64 -S unlink -S unlinkat -S rename -S renameat -F auid>=500 -F auid!=4294967295 -k delete
-a always,exit -F arch=b32 -S unlink -S unlinkat -S rename -S renameat -F auid>=500 -F auid!=4294967295 -k delete

Supportive Information

The following resource is also helpful.

• https://www.cisco.com/c/en/us/td/docs/security/firepower/623/configuration/guide/fpmc-config-guide-v623.htmlhttps://www.cisco.com/c/en/us/td/docs/security/firepower/623/configuration/guide/fpmc-config-guide-v623.html

This security hardening control applies to the following category of controls within NIST 800-53: Audit and Accountability.This control applies to the following type of system Unix.

References

• 800-53|AU-12

Source

• Tenable.com/audits