This analytic identifies the suspicious Remote Thread execution of rundll32.exe to any process. This technique was seen in IcedID malware to execute its malicious code in normal process for defense evasion and to steal sensitive information in the compromised host.
- Type: TTP
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2021-07-29
- Author: Teoderick Contreras, Splunk
- ID: 2dbeee3a-f067-11eb-96c0-acde48001122
Kill Chain Phase
- CIS 10
1 2 3 4 5 `sysmon` EventCode=8 SourceImage = "*\\rundll32.exe" TargetImage = "*.exe" | stats count min(_time) as firstTime max(_time) as lastTime by SourceImage TargetImage TargetProcessId SourceProcessId StartAddress EventCode dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `rundll32_create_remote_thread_to_a_process_filter`
The SPL above uses the following Macros:
rundll32_create_remote_thread_to_a_process_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
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
Associated Analytic Story
|56.0||70||80||rundl32 process $SourceImage$ create a remote thread to process $TargetImage$ in host $dest$|
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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