Name:CHCP Command Execution id:21d236ec-eec1-11eb-b23e-acde48001122 version:3 date:2024-09-30 author:Teoderick Contreras, Splunk status:production type:TTP Description:The following analytic detects the execution of the chcp.exe application, which is used to change the active code page of the console. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process creation events where chcp.exe is executed by cmd.exe with specific command-line arguments. This activity is significant because it can indicate the presence of malware, such as IcedID, which uses this technique to determine the locale region, language, or country of the compromised host. If confirmed malicious, this could lead to further system compromise and data exfiltration. 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=chcp.com Processes.parent_process_name = cmd.exe (Processes.parent_process=*/c* OR Processes.parent_process=*/k*) by Processes.process_name Processes.process Processes.parent_process_name Processes.parent_process Processes.process_id Processes.parent_process_id Processes.dest Processes.user | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `chcp_command_execution_filter`
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:other tools or script may used this to change code page to UTF-* or others References: -https://ss64.com/nt/chcp.html -https://twitter.com/tccontre18/status/1419941156633329665?s=20 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 ("$dest$", "$user$") starthoursago=168 | 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:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'IcedID' - 'Azorult' - 'Forest Blizzard' asset_type:Endpoint confidence:30 impact:30 message:parent process $parent_process_name$ spawning chcp process $process_name$ with parent command line $parent_process$ mitre_attack_id: - 'T1059' observable: name:'dest' type:'Hostname' - role: - 'Victim' name:'user' type:'User' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'process_name' - 'process' - 'parent_process_name' - 'parent_process' - 'process_id' - 'parent_process_id' - 'dest' - 'user' risk_score:9 security_domain:endpoint
