Persistence Via Disk Cleanup Handler - Autorun

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About the rule

Rule Type

Standard

Rule Description

Detects when an attacker modifies values of the Disk Cleanup Handler in the registry to achieve persistence via autorun. The disk cleanup manager is part of the operating system. It displays the dialog box […] The user has the option of enabling or disabling individual handlers by selecting or clearing their check box in the disk cleanup manager's UI. Although Windows comes with a number of disk cleanup handlers, they aren't designed to handle files produced by other applications. Instead, the disk cleanup manager is designed to be flexible and extensible by enabling any developer to implement and register their own disk cleanup handler. Any developer can extend the available disk cleanup services by implementing and registering a disk cleanup handler.

Severity

Trouble

Rule Requirement

Criteria

Action1: actionname = "Registry value modified" AND (OBJECTNAME contains "\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\VolumeCaches" OR (OBJECTNAME endswith "\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\VolumeCaches" AND isExist(OBJECTVALUENAME))) AND (((OBJECTNAME contains "\Autorun" OR (OBJECTNAME contains "\Autorun" OR OBJECTVALUENAME contains "\Autorun")) AND (INFORMATION = "DWORD (0x00000001)" OR (CHANGES = 1 AND NEWTYPE = "REG_DWORD"))) OR ((OBJECTNAME contains "\CleanupString,\PreCleanupString" OR (OBJECTNAME contains "\CleanupString,\PreCleanupString" OR OBJECTVALUENAME contains "\CleanupString,\PreCleanupString")) AND INFORMATION contains "cmd,powershell,rundll32,mshta,cscript,wscript,wsl,\Users\Public\,\Windows\TEMP\,\Microsoft\Windows\Start Menu\Programs\Startup")) select Action1.HOSTNAME,Action1.MESSAGE,Action1.OBJECTNAME,Action1.PROCESSNAME,Action1.PREVVAL,Action1.CHANGES

Detection

Execution Mode

realtime

Log Sources

Windows

Author

Nasreddine Bencherchali (Nextron Systems)