Potentially Suspicious Command Executed Via Run Dialog Box - Registry

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About the rule

Rule Type

Standard

Rule Description

Detects execution of commands via the run dialog box on Windows by checking values of the "RunMRU" registry key. This technique was seen being abused by threat actors to deceive users into pasting and executing malicious commands, often disguised as CAPTCHA verification steps.

Severity

Trouble

Rule Requirement

Criteria

Action1: actionname = "Registry value modified" AND (OBJECTNAME contains "\Microsoft\Windows\CurrentVersion\Explorer\RunMRU" OR (OBJECTNAME endswith "\Microsoft\Windows\CurrentVersion\Explorer" AND OBJECTVALUENAME startswith "RunMRU")) AND ((INFORMATION contains "powershell,pwsh" AND INFORMATION contains " -e , -ec , -en , -enc , -enco,ftp,Hidden,http,iex,Invoke-") OR (INFORMATION contains "wmic" AND INFORMATION contains "shadowcopy,process call create")) select Action1.HOSTNAME,Action1.MESSAGE,Action1.OBJECTNAME,Action1.PROCESSNAME,Action1.PREVVAL,Action1.CHANGES

Detection

Execution Mode

realtime

Log Sources

Windows

Author

Ahmed Farouk, Nasreddine Bencherchali