Windows Hijack Execution Flow Version Dll Side Load

Description

The following analytic detects a process loading a version.dll file from a directory other than %windir%\system32 or %windir%\syswow64. This detection leverages Sysmon EventCode 7 to identify instances where an unsigned or improperly located version.dll is loaded. This activity is significant as it is a common technique used in ransomware and APT malware campaigns, including Brute Ratel C4, to execute malicious code via DLL side loading. If confirmed malicious, this could allow attackers to execute arbitrary code, maintain persistence, and potentially compromise the target host.

Query · spl

`sysmon` EventCode=7 ImageLoaded = "*\\version.dll" AND (Signed = "false" OR NOT(ImageLoaded IN("*\\windows\\system32*",  "*\\windows\\syswow64\\*"))) | fillnull | stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded dest loaded_file loaded_file_path original_file_name process_exec process_guid process_hash process_id process_name process_path service_dll_signature_exists service_dll_signature_verified signature signature_id user_id vendor_product | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_hijack_execution_flow_version_dll_side_load_filter`

Implementation guide

The latest Sysmon TA 3.0 https://splunkbase.splunk.com/app/5709 will add the ImageLoaded name to the process_name field, allowing this query to work. Use as an example and implement for other products.

Known false positives

  • No false positives have been identified at this time.

Analyst notes

Known false positives: No false positives have been identified at this time.

Raw source Windows Hijack Execution Flow Version Dll Side Load · SPL
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Published by splunk/security_content ↗, licensed under Apache 2.0 ↗. Reproduced here unmodified. 
name: Windows Hijack Execution Flow Version Dll Side Load
id: 8351340b-ac0e-41ec-8b07-dd01bf32d6ea
version: 14
creation_date: '2022-08-30'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects a process loading a version.dll file from a directory other than %windir%\system32 or %windir%\syswow64. This detection leverages Sysmon EventCode 7 to identify instances where an unsigned or improperly located version.dll is loaded. This activity is significant as it is a common technique used in ransomware and APT malware campaigns, including Brute Ratel C4, to execute malicious code via DLL side loading. If confirmed malicious, this could allow attackers to execute arbitrary code, maintain persistence, and potentially compromise the target host.
data_source:
    - Sysmon EventID 7
search: '`sysmon` EventCode=7 ImageLoaded = "*\\version.dll" AND (Signed = "false" OR NOT(ImageLoaded IN("*\\windows\\system32*",  "*\\windows\\syswow64\\*"))) | fillnull | stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded dest loaded_file loaded_file_path original_file_name process_exec process_guid process_hash process_id process_name process_path service_dll_signature_exists service_dll_signature_verified signature signature_id user_id vendor_product | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_hijack_execution_flow_version_dll_side_load_filter`'
how_to_implement: The latest Sysmon TA 3.0 https://splunkbase.splunk.com/app/5709 will add the ImageLoaded name to the process_name field, allowing this query to work. Use as an example and implement for other products.
known_false_positives: No false positives have been identified at this time.
references:
    - https://www.mdsec.co.uk/2022/08/part-3-how-i-met-your-beacon-brute-ratel/
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"
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: a process $Image$ loading $ImageLoaded$ as a side load dll on $dest$
analytic_story:
    - SolarWinds WHD RCE Post Exploitation
    - Brute Ratel C4
    - XWorm
    - Malicious Inno Setup Loader
asset_type: Endpoint
mitre_attack_id:
    - T1574.001
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/brute_ratel/iso_version_dll_campaign/sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

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