Detection: Deny Permission using Cacls Utility

Description

The following analytic identifies the use of cacls.exe, icacls.exe or xcacls.exe placing the deny permission on a file or directory. Adversaries perform this behavior to prevent responders from reviewing or gaining access to adversary files on disk.

Annotations

No annotations available.

Implementation

To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA. Tune and filter known instances where renamed icacls.exe may be used.

Known False Positives

System administrators may use cacls utilities but this is not a common practice. Filter as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
A cacls process $process_name$ with commandline $process$ try to deny a permission of a file or directory in host $dest_device_id$ 35 50 70
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References


Version: 7