Sigma rule: Suspicious PowerShell Invocations - Specific - ProcessCreation

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-395e9cf9df12, updated 2023-01-05T00:00:00.000Z.

Rule

Title
Suspicious PowerShell Invocations - Specific - ProcessCreation
Status
test
Level
medium
Author
Nasreddine Bencherchali (Nextron Systems)
Date
2023-01-05
File
rules/windows/process_creation/proc_creation_win_powershell_invocation_specific.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects suspicious PowerShell invocation command parameters

Log source

product
windows
category
process_creation

Detection

selection_convert_b64:
    CommandLine|contains|all:
        - '-nop'
        - ' -w '
        - 'hidden'
        - ' -c '
        - '[Convert]::FromBase64String'
selection_iex:
    CommandLine|contains|all:
        - ' -w '
        - 'hidden'
        - '-noni'
        - '-nop'
        - ' -c '
        - 'iex'
        - 'New-Object'
selection_enc:
    CommandLine|contains|all:
        - ' -w '
        - 'hidden'
        - '-ep'
        - 'bypass'
        - '-Enc'
selection_reg:
    CommandLine|contains|all:
        - 'powershell'
        - 'reg'
        - 'add'
        - '\software\'
selection_webclient:
    CommandLine|contains|all:
        - 'bypass'
        - '-noprofile'
        - '-windowstyle'
        - 'hidden'
        - 'new-object'
        - 'system.net.webclient'
        - '.download'
selection_iex_webclient:
    CommandLine|contains|all:
        - 'iex'
        - 'New-Object'
        - 'Net.WebClient'
        - '.Download'
filter_chocolatey:
    CommandLine|contains:
        - "(New-Object System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1"
        - 'Write-ChocolateyWarning'
condition: 1 of selection_* and not 1 of filter_*

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.stealth

Related rules

References

  • Internal Research

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_powershell_invocation_specific.yml

Sources and licences

  • SigmaHQ

    "Suspicious PowerShell Invocations - Specific - ProcessCreation" by Nasreddine Bencherchali (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_powershell_invocation_specific.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: Suspicious PowerShell Invocations - Specific - ProcessCreation",
entity page, dataset version ref-395e9cf9df12, updated 2023-01-05T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/536e2947-3729-478c-9903-745aaffe60d2 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 536e2947-3729-478c-9903-745aaffe60d2, 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.