Detection: Windows Network Share Interaction With Net

Updated Date: 2024-11-26 ID: 4dc3951f-b3f8-4f46-b412-76a483f72277 Author: Dean Luxton Type: TTP Product: Splunk Enterprise Security

Description

This analytic detects network share discovery and collection activities performed on Windows systems using the Net command. Attackers often use network share discovery to identify accessible shared resources within a network, which can be a precursor to privilege escalation or data exfiltration. By monitoring Windows Event Logs for the usage of the Net command to list and interact with network shares, this detection helps identify potential reconnaissance and collection activities.

1
2| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime values(Processes.user_category) as user_category values(Processes.user_bunit) as user_bunit  FROM datamodel=Endpoint.Processes WHERE `process_net` BY Processes.user Processes.dest Processes.process_exec Processes.parent_process_exec Processes.process Processes.parent_process 
3| `drop_dm_object_name(Processes)` 
4| regex process="net[\s\.ex1]+view
5|net[\s\.ex1]+share
6|net[\s\.ex1]+use\s" 
7| `security_content_ctime(firstTime)` 
8| `security_content_ctime(lastTime)` 
9| `windows_network_share_interaction_with_net_filter`

Data Source

Name Platform Sourcetype Source
Sysmon EventID 1 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Name Value
process_net (Processes.process_name="net.exe" OR Processes.original_file_name="net.exe" OR Processes.process_name="net1.exe" OR Processes.original_file_name="net1.exe")
windows_network_share_interaction_with_net_filter search *
windows_network_share_interaction_with_net_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1135 Network Share Discovery Discovery
T1039 Data from Network Shared Drive Collection
KillChainPhase.EXPLOITAITON
NistCategory.DE_CM
Cis18Value.CIS_10
APT1
APT32
APT38
APT39
APT41
Chimera
DarkVishnya
Dragonfly
FIN13
INC Ransom
Sowbug
Tonto Team
Tropic Trooper
Wizard Spider
APT28
BRONZE BUTLER
Chimera
Fox Kitten
Gamaredon Group
RedCurl
Sowbug
menuPass

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 Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

The detection is based on data originating from either Endpoint Detection and Response (EDR) telemetry or EventCode 4688 with process command line logging enabled. These sources provide security-related telemetry from the endpoints. To implement this search, you must ingest logs that contain the process name, parent process, and complete command-line executions. These logs must be mapped to the Splunk Common Information Model (CIM) to normalize the field names capture the data within the datamodel schema.

Known False Positives

Unknown

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
User $user$ leveraged net.exe on $dest$ to interact with network shares, executed by parent process $parent_process$ 20 20 100
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

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: 3