Detectionmediumstable

Linux Logs Clearing Attempts

Detects logs clearing attempts on Linux systems via utilities such as 'rm', 'rmdir', 'shred', and 'unlink' targeting log files and directories. Adversaries often try to clear logs to cover their tracks after performing malicious activities.

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Launch

Ömer Günal, oscd.communityCreated Wed Oct 07Updated Wed Mar 1880915f59-9b56-4616-9de0-fd0dea6c12felinux

Log Source

LinuxProcess Creation

ProductLinux← raw: linux

CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic

detection:
    selection:
        Image|endswith:
            - '/rm'    # covers /rmdir as well
            - '/rmdir'
            - '/shred'
            - '/unlink'
        CommandLine|contains:
            - '/var/log'
            - '/var/spool/mail'
    filter_main_legit_systat:
        Image|endswith: '/rm'
        CommandLine|startswith: 'rm -f /var/log/sysstat/'
    filter_main_dmseg:
        Image|endswith: '/rm'
        CommandLine|startswith: 'rm -f -- /var/log//dmesg' # // before dmesg is not typo
    condition: selection and not 1 of filter_main_*