Name:Windows Hijack Execution Flow Version Dll Side Load id:8351340b-ac0e-41ec-8b07-dd01bf32d6ea version:3 date:2024-09-30 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\\*"))) | stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded process_name dest EventCode Signed ProcessId | `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:unknown 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 ("$dest$") 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: - 'Brute Ratel C4' asset_type:Endpoint confidence:70 impact:50 message:a process $Image$ loading $ImageLoaded$ as a side load dll in $dest$ mitre_attack_id: - 'T1574.001' - 'T1574' 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' risk_score:35 security_domain:endpoint
