Windows WinRAR Launched Outside Default Installation Directory

 Original Source: [splunk source]
Name:Windows WinRAR Launched Outside Default Installation Directory
id:3b711292-9793-4a88-8e89-6e016cfbc09c
version:3
date:None
author:Teoderick Contreras, Splunk
status:production
type:Anomaly
Description:This Analytics detects the execution of WinRAR or RAR outside the default installation directory. This behavior can be significant as it could indicate attempts to archive collected sensitive data from the endpoint for exfiltration. We recommend reviewing the process path and the parent process path to determine if the execution is legitimate and if possible validate the data being archived.
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 ("Winrar.exe", "rar.exe")
NOT Processes.process_path IN (
"*:\\Program Files (x86)\\WinRAR\\*",
"*:\\Program Files\\WinRAR\\*"
)
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)`
| `windows_winrar_launched_outside_default_installation_directory_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:False positives are expected from machines where the default installation path was changed. Apply additional filters accordingly.
References:
  -https://malpedia.caad.fkie.fraunhofer.de/details/py.blankgrabber
drilldown_searches:
 name:'View the detection results for - "$user$" and "$dest$"'
 search:'%original_detection_search% | search user = "$user$" dest = "$dest$"'
 earliest_offset:'$info_min_time$'
 latest_offset:'$info_max_time$'
 name:'View risk events for the last 7 days for - "$user$" and "$dest$"'
 search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") | 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:['BlankGrabber Stealer']

asset_type:Endpoint

mitre_attack_id:['T1047']

product:['Splunk Enterprise', 'Splunk Enterprise Security', 'Splunk Cloud']

category:endpoint

security_domain:endpoint

tags:

tests:
 name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1047/susp_winrar/blank123.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
 test_type:'unit'
manual_test:None

Related Analytic Stories


BlankGrabber Stealer