Detection: Windows Dir Piped to Findstr Activity

Description

The following analytic detects the execution of the dir command piped to findstr on Windows systems. This technique is commonly used by attackers during the reconnaissance phase to enumerate files, directories, or sensitive data by filtering directory listings for specific strings or patterns. While this command combination can have legitimate administrative uses, adversaries frequently leverage it to locate credentials, configuration files, or other high-value targets on a compromised system. If confirmed malicious, this activity could indicate an attacker is actively mapping the file system in preparation for data exfiltration, lateral movement, or further exploitation.

Search

 1
 2| tstats `security_content_summariesonly`
 3   count min(_time) as firstTime
 4         max(_time) as lastTime
 5
 6from datamodel=Endpoint.Processes where
 7
 8Processes.process="*dir *
 9|*findstr *"
10
11by Processes.process Processes.vendor_product Processes.user_id Processes.process_hash
12   Processes.parent_process_name Processes.parent_process_exec Processes.action
13   Processes.dest Processes.process_current_directory Processes.process_path
14   Processes.process_integrity_level Processes.original_file_name
15   Processes.parent_process Processes.parent_process_path Processes.parent_process_guid
16   Processes.parent_process_id Processes.process_guid
17   Processes.process_id Processes.user Processes.process_name
18
19
20| `drop_dm_object_name(Processes)`
21
22| `security_content_ctime(firstTime)`
23
24| `security_content_ctime(lastTime)`
25
26| `windows_dir_piped_to_findstr_activity_filter`

Data Source

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

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

Legitimate administrative tasks and scripts may use dir piped to findstr for routine file searches. Filter based on known user behavior and approved administrative activity.

Associated Analytic Story

• Suspicious Command-Line Executions

• Windows Discovery Techniques

• Active Directory Discovery

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: 1