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Windows RunMRU Registry Key or Value Deleted

The following analytic detects the deletion or modification of Most Recently Used (MRU) command entries stored within the Windows Registry. Adversaries often clear these registry keys, such as…

Description

The following analytic detects the deletion or modification of Most Recently Used (MRU) command entries stored within the Windows Registry. Adversaries often clear these registry keys, such as HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU, to remove forensic evidence of commands executed via the Windows Run dialog or other system utilities. This activity aims to obscure their actions, hinder incident response efforts, and evade detection. Detection focuses on monitoring for changes (deletion of values or modification of the MRUList value) to these specific registry paths, particularly when performed by unusual processes or outside of typical user behavior. Anomalous deletion events can indicate an attempt at defense evasion or post-exploitation cleanup by a malicious actor.

Detection logic

Detection requirements

Platform
Windows

The rule states no platform. This is derived from the ATT&CK technique it maps to.

Log source category
sysmon_eventid_12

Known benign triggers

  • This event can be seen when administrator delete a history manually or uninstall/reinstall a software that creates MRU registry entry. It is recommended to check this alert with high priority.

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