Sigma rule: Potentially Suspicious Powershell Script Execution From Temp Folder

Rule

Title

Potentially Suspicious Powershell Script Execution From Temp Folder

Status

test

Level

medium

Author

Florian Roth (Nextron Systems), Max Altgelt (Nextron Systems), Tim Shelton

Date

2021-07-14

Modified

2026-02-17

File

rules/windows/process_creation/proc_creation_win_powershell_script_exec_from_temp_folder.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects a potentially suspicious powershell script executions from temporary folder

Log source

product

windows

category

process_creation

Detection

selection:
    Image|endswith:
        - '\powershell.exe'
        - '\pwsh.exe'
    CommandLine|contains:
        - '\Windows\Temp'
        - '\Temporary Internet'
        - '\AppData\Local\Temp'
        - '\AppData\Roaming\Temp'
        - '%TEMP%'
        - '%TMP%'
        - '%LocalAppData%\Temp'
filter_optional_vscode:
    CommandLine|contains: '-WindowStyle hidden -Verb runAs'
filter_optional_amazon_ec2:
    CommandLine|contains: '\Windows\system32\config\systemprofile\AppData\Local\Temp\Amazon\EC2-Windows\'
filter_optional_generic:
    CommandLine|contains:
        - ' >'
        - 'Out-File'
        - 'ConvertTo-Json'
filter_optional_chocolatey_installer:
    ParentImage:
        - 'C:\Windows\System32\Msiexec.exe'
        - 'C:\Windows\SysWOW64\Msiexec.exe'
    Image|endswith: '\powershell.exe'
    CommandLine|contains|all:
        - '-NoProfile -ExecutionPolicy Bypass -Command'
        - 'AppData\Local\Temp\'
        - 'Install-Chocolatey.ps1'
condition: selection and not 1 of filter_optional_*

False positives (as the rule lists them)

• Administrative scripts

Tags

• attack.execution
• attack.t1059.001

MITRE ATT&CK ids this rule names

• T1059.001

References

• https://www.microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploit/

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_script_exec_from_temp_folder.yml