Name:Icacls Deny Command id:cf8d753e-a8fe-11eb-8f58-acde48001122 version:15 date:None author:Teoderick Contreras, Splunk status:production type:Anomaly Description:The following analytic detects instances where an adversary modifies security permissions of a file or directory using commands like "icacls.exe", "cacls.exe", or "xcacls.exe" with deny options.
It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions.
This activity is significant as it is commonly used by Advanced Persistent Threats (APTs) and coinminer scripts to evade detection and impede access to critical files.
If confirmed malicious, this could allow attackers to maintain persistence and hinder incident response efforts.
Data_source:
-Sysmon EventID 1
-Windows Event Log Security 4688
-CrowdStrike ProcessRollup2
search:| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime
From datamodel=Endpoint.Processes Where
Processes.process_name IN ( "icacls.exe", "cacls.exe", "xcacls.exe" ) Processes.process IN ( "*/deny*", "*/d:*", "*/d *" )
how_to_implement:The detection is based on data that originates from Endpoint Detection
and Response (EDR) agents. These agents are designed to provide security-related
telemetry from the endpoints where the agent is installed. To implement this search,
you must ingest logs that contain the process GUID, process name, and parent process.
Additionally, you must ingest complete command-line executions. These logs must
be processed using the appropriate Splunk Technology Add-ons that are specific to
the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint`
data model. Use the Splunk Common Information Model (CIM) to normalize the field
names and speed up the data modeling process.
known_false_positives:No false positives have been identified at this time. Filter as needed. References: -https://thedfirreport.com/2020/04/20/sqlserver-or-the-miner-in-the-basement/ drilldown_searches: name:'View the detection results for - "$dest$" and "$user$"' search:'%original_detection_search% | search dest = "$dest$" user = "$user$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$" and "$user$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'7d' latest_offset:'0' analytic_story:['Azorult', 'Sandworm Tools', 'Compromised Windows Host', 'XMRig', 'Crypto Stealer', 'Defense Evasion or Unauthorized Access Via SDDL Tampering']
