This analytic is to detect a process loading version.dll that is not in %windir%\system32 or %windir%\syswow64 dir path. This event is seen in ransomware and APT malware that executes malicious version.dll placed in the same folder of onedrive application that will execute that module. This technique is known to be DLL side loading. This technique was used to execute an agent of Brute Ratel C4 red teaming tools to serve as remote admin tool to collect and compromise target host.
- Type: Anomaly
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2022-08-24
- Author: Teoderick Contreras, Splunk
- ID: 8351340b-ac0e-41ec-8b07-dd01bf32d6ea
Kill Chain Phase
- CIS 10
1 2 3 4 5 `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`
The SPL above uses the following Macros:
windows_hijack_execution_flow_version_dll_side_load_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
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
Associated Analytic Story
|35.0||50||70||a process $Image$ loading $ImageLoaded$ as a side load dll in $dest$|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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