Detection: Windows Set Account Password Policy To Unlimited Via Net

Updated Date: 2025-01-13 ID: 11f93009-8083-43fd-82a7-821fcbdc8342 Author: Teoderick Contreras, Nasreddine Bencherchali, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects the use of net.exe to update user account policies to set passwords as non-expiring. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions involving "/maxpwage:unlimited" or "/maxpwage:49710", which achieve a similar outcome theoretically. This activity is significant as it can indicate an attempt to maintain persistence, escalate privileges, evade defenses, or facilitate lateral movement. If confirmed malicious, this behavior could allow an attacker to maintain long-term access to compromised accounts, potentially leading to further exploitation and unauthorized access to sensitive information.

Search

1
2| tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_net` AND Processes.process="* accounts *" AND (Processes.process="* /maxpwage:unlimited" OR Processes.process="/maxpwage:49710") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id 
3| `drop_dm_object_name(Processes)` 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `windows_set_account_password_policy_to_unlimited_via_net_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

Name	Value
process_net	`(Processes.process_name="net1.exe" OR Processes.original_file_name="net1.exe")`
windows_set_account_password_policy_to_unlimited_via_net_filter	`search *`

windows_set_account_password_policy_to_unlimited_via_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
T1489	Service Stop	Impact

Actions on Objectives

DE.AE

CIS 10

Indrik Spider

LAPSUS$

Lazarus Group

Sandworm Team

Wizard Spider

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

This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

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

This behavior is not commonly seen in production environment and not advisable, filter as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ attempting to make non-expiring password on host user accounts.

Risk Object	Risk Object Type	Risk Score	Threat Objects
dest	system	100	No Threat Objects

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: 1