Suspicious GPUpdate no Command Line Arguments
Description
The following analytic identifies gpupdate.exe with no command line arguments. It is unusual for gpupdate.exe to execute with no command line arguments present. This particular behavior is common with malicious software, including Cobalt Strike. During investigation, identify any network connections and parallel processes. Identify any suspicious module loads related to credential dumping or file writes. gpupdate.exe is natively found in C:\Windows\system32 and C:\Windows\syswow64.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2022-03-15
- Author: Michael Haag, Splunk
- ID: f308490a-473a-40ef-ae64-dd7a6eba284a
Annotations
Kill Chain Phase
- Exploitation
NIST
CIS20
CVE
Search
1
2
3
4
5
6
7
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes where `process_gpupdate` by _time span=1h Processes.process_id Processes.process_name Processes.dest Processes.process_path Processes.process Processes.parent_process_name
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| regex process="(?i)(gpupdate\.exe.{0,4}$)"
| `suspicious_gpupdate_no_command_line_arguments_filter`
Macros
The SPL above uses the following Macros:
suspicious_gpupdate_no_command_line_arguments_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Supported Add-on (TA)
List of Splunk Add-on’s tested to work with the analytic.
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
To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.
Known False Positives
Limited false positives may be present in small environments. Tuning may be required based on parent process.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
49.0 | 70 | 70 | Suspicious gpupdate.exe process with no command line arguments executed on $dest$ by $user$ |
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://raw.githubusercontent.com/xx0hcd/Malleable-C2-Profiles/0ef8cf4556e26f6d4190c56ba697c2159faa5822/crimeware/trick_ryuk.profile
- https://www.cobaltstrike.com/blog/learn-pipe-fitting-for-all-of-your-offense-projects/
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: 3