New Root Certificate Installed Via Certutil.EXE

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About the rule

Rule Type

Standard

Rule Description

Detects execution of "certutil" with the "addstore" flag in order to install a new certificate on the system. Adversaries may install a root certificate on a compromised system to avoid warnings when connecting to adversary controlled web servers.

Severity

Trouble

Rule Requirement

Criteria

Action1: actionname = "Process started" AND (PROCESSNAME endswith "\certutil.exe" OR ORIGINALFILENAME = "CertUtil.exe") AND COMMANDLINE contains "-addstore,/addstore,–addstore,—addstore,―addstore" AND COMMANDLINE contains "root" select Action1.HOSTNAME,Action1.MESSAGE,Action1.COMMANDLINE,Action1.FILE_NAME,Action1.PROCESSNAME,Action1.USERNAME,Action1.PARENTPROCESSNAME

Detection

Execution Mode

realtime

Log Sources

Windows

Author

oscd.community, @redcanary, Zach Stanford @svch0st