Sigma rule: Suspicious Command Patterns In Scheduled Task Creation

Rule

Title

Suspicious Command Patterns In Scheduled Task Creation

Status

test

Level

high

Author

Florian Roth (Nextron Systems)

Date

2022-02-23

Modified

2024-03-19

File

rules/windows/process_creation/proc_creation_win_schtasks_susp_pattern.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects scheduled task creation using "schtasks" that contain potentially suspicious or uncommon commands

Log source

product

windows

category

process_creation

Detection

selection_schtasks:
    Image|endswith: '\schtasks.exe'
    CommandLine|contains: '/Create '
selection_pattern_1:
    CommandLine|contains:
        - '/sc minute '
        - '/ru system '
selection_pattern_2:
    CommandLine|contains:
        - 'cmd /c'
        - 'cmd /k'
        - 'cmd /r'
        - 'cmd.exe /c '
        - 'cmd.exe /k '
        - 'cmd.exe /r '
selection_uncommon:
    CommandLine|contains:
        - ' -decode '
        - ' -enc '
        - ' -w hidden '
        - ' bypass '
        - ' IEX'
        - '.DownloadData'
        - '.DownloadFile'
        - '.DownloadString'
        - '/c start /min ' # https://twitter.com/RedDrip7/status/1506480588827467785
        - 'FromBase64String'
        - 'mshta http'
        - 'mshta.exe http'
selection_anomaly_1:
    CommandLine|contains:
        - ':\ProgramData\'
        - ':\Temp\'
        - ':\Tmp\'
        - ':\Users\Public\'
        - ':\Windows\Temp\'
        - '\AppData\'
        - '%AppData%'
        - '%Temp%'
        - '%tmp%'
selection_anomaly_2:
    CommandLine|contains:
        - 'cscript'
        - 'curl'
        - 'wscript'
condition: selection_schtasks and ( all of selection_pattern_* or selection_uncommon or all of selection_anomaly_* )

False positives (as the rule lists them)

• Software installers that run from temporary folders and also install scheduled tasks are expected to generate some false positives

Tags

• attack.privilege-escalation
• attack.persistence
• attack.execution
• attack.t1053.005

MITRE ATT&CK ids this rule names

• T1053.005

References

• https://app.any.run/tasks/512c1352-6380-4436-b27d-bb62f0c020d6/
• https://twitter.com/RedDrip7/status/1506480588827467785
• https://www.ncsc.gov.uk/static-assets/documents/malware-analysis-reports/devil-bait/NCSC-MAR-Devil-Bait.pdf

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_schtasks_susp_pattern.yml