title: Suspicious eventlog clear or configuration using wevtutil
id: cc36992a-4671-4f21-a91d-6c2b72a2edf5
description: Detects clearing or configuration of eventlogs uwing wevtutil, powershell and wmic. Might be used by ransomwares during the attack (seen by NotPetya and others)
author: Ecco, Daniil Yugoslavskiy, oscd.community
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1070/T1070.yaml
    - https://eqllib.readthedocs.io/en/latest/analytics/5b223758-07d6-4100-9e11-238cfdd0fe97.html
date: 2019/09/26
modified: 2019/11/11
tags:
    - attack.defense_evasion
    - attack.t1070
    - car.2016-04-002
level: high
logsource:
    category: process_creation
    product: windows
detection:
    selection_wevtutil:
        Image|endswith: '\wevtutil.exe'
        CommandLine|contains:  
            - 'clear-log' # clears specified log 
            - 'cl'        # short version of 'clear-log'
            - 'set-log'   # modifies config of specified log. could be uset to set it to a tiny size
            - 'sl'        # short version of 'set-log'
    selection_ps:
        Image|endswith: '\powershell.exe'
        CommandLine|contains: 
            - 'Clear-EventLog'
            - 'Remove-EventLog'
            - 'Limit-EventLog'
    selection_wmic:
        Image|endswith: '\wmic.exe'
        CommandLine|contains: 'ClearEventLog'
    condition: 1 of them
falsepositives:
    - Admin activity
    - Scripts and administrative tools used in the monitored environment