Detection: Windows Command and Scripting Interpreter Hunting Path Traversal

Description

The following analytic identifies path traversal command-line executions, leveraging data from Endpoint Detection and Response (EDR) agents. It detects patterns in command-line arguments indicative of path traversal techniques, such as multiple instances of "/..", "..", or "\..". This activity is significant as it often indicates attempts to evade defenses by executing malicious code, such as through msdt.exe. If confirmed malicious, this behavior could allow attackers to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further lateral movement within the network.

Search

 1
 2| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
 3as lastTime FROM datamodel=Endpoint.Processes where
 4Processes.process IN ("*\\..*", "*//..*", "*\..*", "*/..*")
 5by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
 6   Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
 7   Processes.parent_process_name Processes.parent_process_path Processes.process
 8   Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id
 9   Processes.process_integrity_level Processes.process_name Processes.process_path
10   Processes.user Processes.user_id Processes.vendor_product
11
12
13| `drop_dm_object_name("Processes")`
14
15| `security_content_ctime(firstTime)`
16
17| `security_content_ctime(lastTime)`
18
19| eval count_of_pattern1 = (mvcount(split(process,"/.."))-1)
20
21| eval count_of_pattern2 = (mvcount(split(process,"\.."))-1)
22
23| eval count_of_pattern3 = (mvcount(split(process,"\\.."))-1)
24
25| eval count_of_pattern4 = (mvcount(split(process,"//.."))-1)
26
27
28| search count_of_pattern1 > 1
29         OR
30         count_of_pattern2 > 1
31         OR
32         count_of_pattern3 > 1
33         OR
34         count_of_pattern4 > 1
35
36| `windows_command_and_scripting_interpreter_hunting_path_traversal_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	Other	'crowdstrike:events:sensor'	'crowdstrike'
Sysmon EventID 1	Windows	'XmlWinEventLog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Windows Event Log Security 4688	Windows	'XmlWinEventLog'	'XmlWinEventLog:Security'

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

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 may vary depending on the score you want to check.

Associated Analytic Story

• Microsoft Support Diagnostic Tool Vulnerability CVE-2022-30190

• Windows Defense Evasion Tactics

References

• https://app.any.run/tasks/713f05d2-fe78-4b9d-a744-f7c133e3fafb/

Detection Testing

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: 7