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Description

This analytic identifies the suspicious Remote Thread execution of wermgr.exe process to "firefox.exe", "chrome.exe" and other known browsers. This technique was seen in Qakbot malware that executes its malicious code by injecting its code in legitimate Windows Operating System processes such as wermgr.exe to steal information in the compromised host. This TTP detection can be a good pivot to detect wermgr.exe process injected with qakbot code that tries to remote thread code execution in known browsers like firefox and edge which is not a common behavior of this wermgr.exe application.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2022-10-28
  • Author: Teoderick Contreras, Splunk
  • ID: aec755a5-3a2c-4be0-ab34-6540e68644e9

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1055.001 Dynamic-link Library Injection Defense Evasion, Privilege Escalation
T1055 Process Injection Defense Evasion, Privilege Escalation
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 3
  • CIS 5
  • CIS 16
CVE 


1
2
3
4
5



`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 by SourceImage TargetImage SourceProcessGuid SourceProcessId StartAddress StartFunction TargetProcessGuid TargetProcessId  EventCode Computer 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_process_injection_of_wermgr_to_known_browser_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_process_injection_of_wermgr_to_known_browser_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • SourceImage
  • TargetImage
  • SourceProcessGuid
  • SourceProcessId
  • StartAddress
  • StartFunction
  • TargetProcessGuid
  • TargetProcessId
  • EventCode
  • Computer

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

unknown

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
49.0 70 70 wermgr.exe process $SourceImage$ create a remote thread to a browser process $TargetImage$ in host $Computer$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

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