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