Detection: Account Discovery With Net App

Description

The following analytic has been deprecated in favour of the more generic "45e52536-ae42-11eb-b5c6-acde48001122". The following analytic detects potential account discovery activities using the 'net' command, commonly employed by malware like Trickbot for reconnaissance. It leverages Endpoint Detection and Response (EDR) data, focusing on specific command-line patterns and process relationships. This activity is significant as it often precedes further malicious actions, such as lateral movement or privilege escalation. If confirmed malicious, attackers could gain valuable information about user accounts, enabling them to escalate privileges or move laterally within the network, posing a significant security risk.

Search

1
2| tstats `security_content_summariesonly` values(Processes.process) as process values(Processes.parent_process) as parent_process values(Processes.process_id) as process_id count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_net` AND (Processes.process="* user *" OR  Processes.process="*config*" OR Processes.process="*view /all*") by  Processes.process_name Processes.dest Processes.user Processes.parent_process_name 
3| where count >=4 
4| `drop_dm_object_name(Processes)` 
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `account_discovery_with_net_app_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	N/A	'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

Admin or power user may used this series of command.

Associated Analytic Story

• IcedID

• Trickbot

Risk Based Analytics (RBA)

Risk Message:

Suspicious $process_name$ usage detected on endpoint $dest$ by user $user$.

References

• https://labs.vipre.com/trickbot-and-its-modules/

• https://whitehat.eu/incident-response-case-study-featuring-ryuk-and-trickbot-part-2/

• https://app.any.run/tasks/48414a33-3d66-4a46-afe5-c2003bb55ccf/

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: 8