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splunk-security_content/detections/endpoint/chcp_command_execution.yml
Teoderick Contreras fcb5e9977b more_interlock_rat
2025-08-07 13:50:17 +02:00

88 lines
4.2 KiB
YAML

name: CHCP Command Execution
id: 21d236ec-eec1-11eb-b23e-acde48001122
version: 9
date: '2025-08-07'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects the execution of the chcp.com utility,
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. 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
- 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
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
| `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: $info_max_time$
rba:
message: parent process $parent_process_name$ spawning chcp process $process_name$
with parent command line $parent_process$
risk_objects:
- field: dest
type: system
score: 9
- field: user
type: user
score: 9
threat_objects: []
tags:
analytic_story:
- IcedID
- Azorult
- Crypto Stealer
- Quasar RAT
- Forest Blizzard
- Interlock Rat
asset_type: Endpoint
mitre_attack_id:
- T1059
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/icedid/simulated_icedid/windows-sysmon.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: XmlWinEventLog