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Record Successful Creation Attempts to Files - open_by_handle_at O_CREAT

An XCCDF Rule

Description

The open_by_handle_at syscall can be used to create new files when O_CREAT flag is specified. The following audit rules will assure that successful attempts to create a file via open_by_handle_at syscall are collected. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the rules below to a file with suffix .rules in the directory /etc/audit/rules.d. If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the rules below to /etc/audit/audit.rules file. 

-a always,exit -F arch=b32 -S open_by_handle_at -F a2&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create
If the system is 64 bit then also add the following lines: 
-a always,exit -F arch=b64 -S open_by_handle_at -F a2&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create

warning alert: Warning

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping system calls related to the same event is more efficient. See the following example: 
-a always,exit -F arch=b32 -S open_by_handle_at,open_by_handle_at -F a2&0100 -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-create

Rationale

Successful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.

ID
xccdf_org.ssgproject.content_rule_audit_rules_successful_file_modification_open_by_handle_at_o_creat
Severity
Medium
Updated