Windows Scheduled Task Created Via XML

Original Source: [splunk source]
Name:Windows Scheduled Task Created Via XML
id:7e03b682-3965-4598-8e91-a60a40a3f7e4
version:4
date:2024-09-30
author:Teoderick Contreras, Splunk
status:production
type:TTP
Description:The following analytic detects the creation of scheduled tasks in Windows using schtasks.exe with the -create flag and an XML parameter. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and process details. This activity is significant as it is a common technique for establishing persistence or achieving privilege escalation, often used by malware like Trickbot and Winter-Vivern. If confirmed malicious, this could allow attackers to maintain access, execute additional payloads, and potentially lead to data theft or ransomware deployment.
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=schtasks.exe Processes.process=*create* Processes.process="* /xml *" by Processes.user Processes.parent_process_name Processes.parent_process Processes.process_name Processes.process Processes.process_guid Processes.process_id Processes.parent_process_guid Processes.dest
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_scheduled_task_created_via_xml_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:It is possible scripts or administrators may trigger this analytic. Filter as needed based on parent process, application.
References:
  -https://twitter.com/_CERT_UA/status/1620781684257091584
  -https://cert.gov.ua/article/3761104
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:
    - 'Winter Vivern'
    - 'CISA AA23-347A'
    - 'Scheduled Tasks'
    - 'MoonPeak'
  asset_type:Endpoint
  confidence:70
  dataset:
    - 'https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/winter-vivern/scheduledtask/sysmon.log'
  impact:70
  message:A scheduled task process, $process_name$, with 'create' or 'delete' commands present in the command line.
  mitre_attack_id:
    - 'T1053.005'
    - 'T1053'
  observable:
    name:'dest'
    type:'Hostname'
    - role:
      - 'Victim'
    name:'user'
    type:'User'
    - role:
      - 'Victim'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  required_fields:
    - '_time'
    - 'Processes.parent_process_name'
    - 'Processes.parent_process'
    - 'Processes.process_name'
    - 'Processes.process_id'
    - 'Processes.process'
    - 'Processes.dest'
    - 'Processes.user'
    - 'Processes.process_id'
    - 'Processes.parent_process_id'
  risk_score:49
  security_domain:endpoint

tests:
name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/winter-vivern/scheduledtask/sysmon.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
  update_timestamp: True
manual_test:None