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.

Techniques

T1112

Sample rules

Windows RunMRU Registry Key or Value Deleted

source: splunk
technicques:
- T1112

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


| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Registry where Registry.registry_path = "*\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\RunMRU*" Registry.action = deleted by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product 
| `drop_dm_object_name(Registry)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_runmru_registry_key_or_value_deleted_filter`