Windows Indirect Command Execution Via Series Of Forfiles
Description
This analytic is developed to detect suspicious excessive usage of forfiles.exe process. This event was seen in post exploitation tool WINPEAS that was used by Ransomware Prestige. Forfiles command lets you run a command on or pass arguments to multiple files. This Windows OS built-in tool being abused to list all files in specific directory or drive.
- Type: Anomaly
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2022-11-30
- Author: Teoderick Contreras, Splunk
- ID: bfdaabe7-3db8-48c5-80c1-220f9b8f22be
Annotations
Kill Chain Phase
- Exploitation
NIST
- DE.AE
CIS20
- CIS 10
CVE
Search
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| tstats `security_content_summariesonly` values(Processes.process) as process values(Processes.process_guid) as process_guid values(Processes.process_name) as process_name count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name = "forfiles.exe" OR Processes.original_file_name = "forfiles.exe" by Processes.parent_process_name Processes.parent_process Processes.dest Processes.user _time span=1m
| where count >=20
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_indirect_command_execution_via_series_of_forfiles_filter`
Macros
The SPL above uses the following Macros:
windows_indirect_command_execution_via_series_of_forfiles_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
To successfully implement this search, you must be ingesting data that records registry activity from your hosts to populate the endpoint data model in the registry node. This is typically populated via endpoint detection-and-response product, such as Carbon Black or endpoint data sources, such as Sysmon. The data used for this search is typically generated via logs that report reads and writes to the registry.
Known False Positives
unknown
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
9.0 | 30 | 30 | excessive forfiles process execution 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.
Reference
- https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/forfiles
- https://github.com/carlospolop/PEASS-ng/tree/master/winPEAS
- https://www.microsoft.com/en-us/security/blog/2022/10/14/new-prestige-ransomware-impacts-organizations-in-ukraine-and-poland/
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: 1