ID | Technique | Tactic |
---|---|---|
T1069.001 | Local Groups | Discovery |
Detection: Windows Admin Permission Discovery
Description
The following analytic identifies the creation of a suspicious file named 'win.dat' in the root directory (C:). It leverages data from the Endpoint.Filesystem datamodel to detect this activity. This behavior is significant as it is commonly used by malware like NjRAT to check for administrative privileges on a compromised host. If confirmed malicious, this activity could indicate that the malware has administrative access, allowing it to perform high-privilege actions, potentially leading to further system compromise and persistence.
Search
1
2|tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Filesystem where Filesystem.file_name IN ("*.exe", "*.dll", "*.sys", "*.com", "*.vbs", "*.vbe", "*.js", "*.bat", "*.cmd", "*.pif", "*.lnk", "*.dat") by Filesystem.dest Filesystem.file_create_time Filesystem.process_id Filesystem.process_guid Filesystem.file_name Filesystem.file_path Filesystem.user
3| `drop_dm_object_name(Filesystem)`
4| eval dropped_file_path = split(file_path, "\\")
5| eval dropped_file_path_split_count = mvcount(dropped_file_path)
6| eval root_drive = mvindex(dropped_file_path,0)
7| where LIKE(root_drive, "C:") AND dropped_file_path_split_count = 2
8| `security_content_ctime(firstTime)`
9| `security_content_ctime(lastTime)`
10| `windows_admin_permission_discovery_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
Sysmon EventID 11 | Windows | 'xmlwineventlog' |
'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational' |
N/A |
Macros Used
Name | Value |
---|---|
security_content_ctime | convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$) |
windows_admin_permission_discovery_filter | search * |
windows_admin_permission_discovery_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
Setting | Value |
---|---|
Disabled | true |
Cron Schedule | 0 * * * * |
Earliest Time | -70m@m |
Latest Time | -10m@m |
Schedule Window | auto |
Creates Risk Event | True |
Implementation
To successfully implement this search you need to be ingesting information on process that include the name of the Filesystem responsible for the changes from your endpoints into the Endpoint
datamodel in the Filesystem
node.
Known False Positives
False positives may occur if there are legitimate accounts with the privilege to drop files in the root of the C drive. It's recommended to verify the legitimacy of such actions and the accounts involved.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
A file was created in root drive C:/ on host - $dest$ | 25 | 50 | 50 |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | XmlWinEventLog:Microsoft-Windows-Sysmon/Operational |
xmlwineventlog |
Integration | ✅ Passing | Dataset | XmlWinEventLog:Microsoft-Windows-Sysmon/Operational |
xmlwineventlog |
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: GitHub | Version: 2