Sigma rule: Malicious Base64 Encoded Powershell Invoke Cmdlets

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-33eaeb2112f5, updated 2023-01-30T00:00:00.000Z.

SigmaHQ marks this rule as deprecated.

Rule

Title
Malicious Base64 Encoded Powershell Invoke Cmdlets
Status
deprecated
Level
high
Author
pH-T (Nextron Systems)
Date
2022/05/31
Modified
2023/01/30
File
deprecated/windows/proc_creation_win_powershell_base64_invoke_susp_cmdlets.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects base64 encoded powershell cmdlet invocation of known suspicious cmdlets

Log source

product
windows
category
process_creation

Detection

selection:
    CommandLine|contains:
        # Invoke-BloodHound
        - 'SQBuAHYAbwBrAGUALQBCAGwAbwBvAGQASABvAHUAbgBkA'
        - 'kAbgB2AG8AawBlAC0AQgBsAG8AbwBkAEgAbwB1AG4AZA'
        - 'JAG4AdgBvAGsAZQAtAEIAbABvAG8AZABIAG8AdQBuAGQA'
        # Invoke-Mimikatz
        - 'SQBuAHYAbwBrAGUALQBNAGkAbQBpAGsAYQB0AHoA'
        - 'kAbgB2AG8AawBlAC0ATQBpAG0AaQBrAGEAdAB6A'
        - 'JAG4AdgBvAGsAZQAtAE0AaQBtAGkAawBhAHQAeg'
        # Invoke-WMIExec
        - 'SQBuAHYAbwBrAGUALQBXAE0ASQBFAHgAZQBjA'
        - 'kAbgB2AG8AawBlAC0AVwBNAEkARQB4AGUAYw'
        - 'JAG4AdgBvAGsAZQAtAFcATQBJAEUAeABlAGMA'
condition: selection

False positives (as the rule lists them)

  • Unlikely

Tags

  • attack.execution
  • attack.t1059.001
  • attack.defense_evasion
  • attack.t1027

MITRE ATT&CK ids this rule names

Related rules

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/deprecated/windows/proc_creation_win_powershell_base64_invoke_susp_cmdlets.yml

Sources and licences

  • SigmaHQ

    "Malicious Base64 Encoded Powershell Invoke Cmdlets" by pH-T (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/deprecated/windows/proc_creation_win_powershell_base64_invoke_susp_cmdlets.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Malicious Base64 Encoded Powershell Invoke Cmdlets",
entity page, dataset version ref-33eaeb2112f5, updated 2023-01-30T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/fd6e2919-3936-40c9-99db-0aa922c356f7 (accessed 2026-11-03).
Underlying source: SigmaHQ rule fd6e2919-3936-40c9-99db-0aa922c356f7, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.