splunk_escuTTP

Windows Process Injection Of Wermgr to Known Browser

The following analytic identifies the suspicious remote thread execution of the wermgr.exe process into known browsers such as firefox.exe, chrome.exe, and others. It leverages Sysmon EventCode 8 logs to detect this behavior by monitoring SourceImage and TargetImage fields. This activity is significant because it is indicative of Qakbot malware, which injects malicious code into legitimate processes to steal information. If confirmed malicious, this activity could allow attackers to execute arbitrary code, escalate privileges, and exfiltrate sensitive data from the compromised host.

Detection Query

`sysmon`
EventCode=8
SourceImage="*\\wermgr.exe"
TargetImage IN ("*\\firefox.exe", "*\\chrome.exe", "*\\iexplore.exe","*\\microsoftedgecp.exe")
| stats count min(_time) as firstTime
              max(_time) as lastTime
              values(NewThreadId) as "NewThreadId"
              values(StartAddress) as "StartAddress"
  by dest signature_id signature
     SourceProcessGuid SourceProcessId SourceImage
     TargetProcessGuid TargetProcessId TargetImage
     StartModule StartFunction
     SourceUser TargetUser vendor_product
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_process_injection_of_wermgr_to_known_browser_filter`

Author

Teoderick Contreras, Splunk

Data Sources

Sysmon EventID 8

References

Raw Content

name: Windows Process Injection Of Wermgr to Known Browser
id: aec755a5-3a2c-4be0-ab34-6540e68644e9
version: 12
creation_date: '2022-10-28'
modification_date: '2026-06-29'
author: Teoderick Contreras, Splunk
status: deprecated
type: TTP
description: The following analytic identifies the suspicious remote thread execution of the wermgr.exe process into known browsers such as firefox.exe, chrome.exe, and others. It leverages Sysmon EventCode 8 logs to detect this behavior by monitoring SourceImage and TargetImage fields. This activity is significant because it is indicative of Qakbot malware, which injects malicious code into legitimate processes to steal information. If confirmed malicious, this activity could allow attackers to execute arbitrary code, escalate privileges, and exfiltrate sensitive data from the compromised host.
data_source:
    - Sysmon EventID 8
search: |-
    `sysmon`
    EventCode=8
    SourceImage="*\\wermgr.exe"
    TargetImage IN ("*\\firefox.exe", "*\\chrome.exe", "*\\iexplore.exe","*\\microsoftedgecp.exe")
    | stats count min(_time) as firstTime
                  max(_time) as lastTime
                  values(NewThreadId) as "NewThreadId"
                  values(StartAddress) as "StartAddress"
      by dest signature_id signature
         SourceProcessGuid SourceProcessId SourceImage
         TargetProcessGuid TargetProcessId TargetImage
         StartModule StartFunction
         SourceUser TargetUser vendor_product
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_process_injection_of_wermgr_to_known_browser_filter`
how_to_implement: To successfully implement this search, you need to be ingesting logs with the SourceImage, TargetImage, and EventCode executions from your endpoints related to create remote thread or injecting codes. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.
known_false_positives: No false positives have been identified at this time.
references:
    - https://news.sophos.com/en-us/2022/03/10/qakbot-decoded/
    - https://www.trellix.com/en-us/about/newsroom/stories/research/demystifying-qbot-malware.html
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 ("$dest$") | 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"
finding:
    title: wermgr.exe process $SourceImage$ create a remote thread to a browser process $TargetImage$ in host $dest$
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Qakbot
asset_type: Endpoint
mitre_attack_id:
    - T1055.001
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/qakbot/remote_thread/sysmon_wermgr_remote.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit
deprecation_info:
    reason: Detection has been deprecated. The search is being replaced with a more generic detection that captures the behavior instead of relying on specific source processes.
    removed_in_version: 6.4.0
    replacement_content:
        - Windows Uncommon Remote Thread Creation In Browser Process