Sigma rule: Root Certificate Installed - PowerShell

Rule

Title

Root Certificate Installed - PowerShell

Status

test

Level

medium

Author

oscd.community, @redcanary, Zach Stanford @svch0st

Date

2020-10-10

Modified

2022-12-02

File

rules/windows/powershell/powershell_script/posh_ps_root_certificate_installed.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Adversaries may install a root certificate on a compromised system to avoid warnings when connecting to adversary controlled web servers.

Log source

product

windows

category

ps_script

definition

Requirements: Script Block Logging must be enabled

Detection

selection1:
    ScriptBlockText|contains|all:
        - 'Move-Item'
        - 'Cert:\LocalMachine\Root'
selection2:
    ScriptBlockText|contains|all:
        - 'Import-Certificate'
        - 'Cert:\LocalMachine\Root'
condition: 1 of selection*

False positives (as the rule lists them)

• Help Desk or IT may need to manually add a corporate Root CA on occasion. Need to test if GPO push doesn't trigger FP

Tags

• attack.defense-impairment
• attack.t1553.004

MITRE ATT&CK ids this rule names

• T1553.004

References

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1553.004/T1553.004.md

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/powershell/powershell_script/posh_ps_root_certificate_installed.yml