Name:Powershell Defender Threat Actions Set to Allow id:7dd3ced1-dc48-4998-9bc2-57e6ae5efaa7 version:1 date:None author:Teoderick Contreras, Splunk status:production type:TTP Description:The following analytic detects the setting of the Windows Defender Threat Actions to allow. It leverages data from the Endpoint.Processes data model, specifically monitoring the execution of the `Set-MpPreference` cmdlet with the `-HighThreatDefaultAction`, `-ModerateThreatDefaultAction`, `-LowThreatDefaultAction`, and `-SevereThreatDefaultAction` parameters set to `6`. This activity is significant because it is commonly used by malware such as RATs, bots, or Trojans to evade detection by allowing threats to pass through the Windows Defender antivirus engine. If confirmed malicious, this action could allow an attacker to execute malicious code without being detected by Windows Defender, leading to potential data exfiltration, further system compromise, or persistent access within the environment. 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 `process_powershell` Processes.process="*Set-MpPreference*" ( Processes.process IN ( "*-HighThreatDefaultAction*", "*-ModerateThreatDefaultAction*", "*-LowThreatDefaultAction*", "*-SevereThreatDefaultAction*" ) Processes.process IN ( "* 6*" ) ) by Processes.action Processes.dest Processes.original_file_name Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
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:Limited false positives. However, tune based on scripts that may perform this action. References: -https://www.broadcom.com/support/security-center/protection-bulletin/uac-0252-activity-delivering-shadowsniff-and-salatstealer-malware -https://bazaar.abuse.ch/browse/tag/SalatStealer/ drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | 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:['Salat Stealer']
