Office Product Spawning Rundll32 with no DLL
Description
The following analytic detects any Windows Office Product spawning rundll32.exe
without a .dll
file extension. This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on process and parent process relationships. This activity is significant as it is a known tactic of the IcedID malware family, which can lead to unauthorized code execution. If confirmed malicious, this could allow attackers to execute arbitrary code, potentially leading to data exfiltration, system compromise, or further malware deployment. Immediate investigation and containment are recommended.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2024-05-18
- Author: Michael Haag, Splunk
- ID: c661f6be-a38c-11eb-be57-acde48001122
Annotations
ATT&CK
Kill Chain Phase
- Delivery
NIST
- DE.CM
CIS20
- CIS 10
CVE
Search
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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name IN ("winword.exe","excel.exe","powerpnt.exe","mspub.exe","visio.exe","onenote.exe","onenotem.exe","onenoteviewer.exe","onenoteim.exe", "msaccess.exe", "Graph.exe","winproj.exe") `process_rundll32` (Processes.process!=*.dll*) by Processes.dest Processes.user Processes.parent_process_name Processes.parent_process Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `office_product_spawning_rundll32_with_no_dll_filter`
Macros
The SPL above uses the following Macros:
office_product_spawning_rundll32_with_no_dll_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
- Processes.dest
- Processes.user
- Processes.parent_process_name
- Processes.parent_process
- Processes.original_file_name
- Processes.process_name
- Processes.process
- Processes.process_id
- Processes.parent_process_path
- Processes.process_path
- Processes.parent_process_id
How To Implement
The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes
node of the Endpoint
data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
Known False Positives
False positives should be limited, but if any are present, filter as needed.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
63.0 | 70 | 90 | office parent process $parent_process_name$ will execute a suspicious child process $process_name$ with process id $process_id$ and no dll commandline $process$ 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.
Reference
- https://www.joesandbox.com/analysis/395471/0/html
- https://app.any.run/tasks/cef4b8ba-023c-4b3b-b2ef-6486a44f6ed9/
- https://any.run/malware-trends/icedid
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
source | version: 6