Wbemprox COM Object Execution

Original Source: [splunk source]
Name:Wbemprox COM Object Execution
id:9d911ce0-c3be-11eb-b177-acde48001122
version:3
date:2024-09-30
author:Teoderick Contreras, Splunk
status:production
type:TTP
Description:The following analytic detects a suspicious process loading a COM object from wbemprox.dll, fastprox.dll, or wbemcomn.dll. It leverages Sysmon EventCode 7 to identify instances where these DLLs are loaded by processes not typically associated with them, excluding known legitimate processes and directories. This activity is significant as it may indicate an attempt by threat actors to abuse COM objects for privilege escalation or evasion of detection mechanisms. If confirmed malicious, this could allow attackers to gain elevated privileges or maintain persistence within the environment, posing a significant security risk.
Data_source:
  • -Sysmon EventID 7
search:`sysmon` EventCode=7 ImageLoaded IN ("*\\fastprox.dll", "*\\wbemprox.dll", "*\\wbemcomn.dll") NOT (process_name IN ("wmiprvse.exe", "WmiApSrv.exe", "unsecapp.exe")) NOT(Image IN("*\\windows\\*","*\\program files*", "*\\wbem\\*"))
| stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded process_name dest EventCode Signed ProcessId Hashes IMPHASH
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `wbemprox_com_object_execution_filter`


how_to_implement:To successfully implement this search, you need to be ingesting logs with the process name and imageloaded executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.
known_false_positives:legitimate process that are not in the exception list may trigger this event.
References:
  -https://krebsonsecurity.com/2021/05/a-closer-look-at-the-darkside-ransomware-gang/
  -https://www.mcafee.com/blogs/other-blogs/mcafee-labs/mcafee-atr-analyzes-sodinokibi-aka-revil-ransomware-as-a-service-what-the-code-tells-us/
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 ("$dest$") 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:
    - 'Ransomware'
    - 'Revil Ransomware'
    - 'LockBit Ransomware'
  asset_type:Endpoint
  confidence:50
  impact:70
  message:Suspicious COM Object Execution on $dest$
  mitre_attack_id:
    - 'T1218'
    - 'T1218.003'
  observable:
    name:'dest'
    type:'Endpoint'
    - role:
      - 'Victim'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  required_fields:
    - '_time'
    - 'Image'
    - 'ImageLoaded'
    - 'process_name'
    - 'dest'
    - 'EventCode'
    - 'Signed'
    - 'ProcessId'
    - 'Hashes'
    - 'IMPHASH'
  risk_score:35
  security_domain:endpoint

tests:
name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/revil/inf2/windows-sysmon.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
manual_test:None