Detection rules › Splunk

Windows Set Account Password Policy To Unlimited Via Net

Status
production
Severity
low
Group by
IntegrityLevel, command_line, computer_name, event_action, original_file_name, parent_command_line, parent_process_guid, parent_process_id, parent_process_name, process_guid, process_hash, process_id, process_name, user, user_id, vendor_product
Author
Teoderick Contreras, Nasreddine Bencherchali, Splunk
Source
github.com/splunk/security_content

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.

Known false positives

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

MITRE ATT&CK coverage

TacticTechniques
Impact

Telemetry coverage

Rule body

name: Windows Set Account Password Policy To Unlimited Via Net
id: 11f93009-8083-43fd-82a7-821fcbdc8342
version: 7
creation_date: '2022-06-24'
modification_date: '2026-05-13'
author: Teoderick Contreras, Nasreddine Bencherchali, Splunk
status: production
type: Anomaly
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.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
search: |-
    | 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.action Processes.dest Processes.original_file_name
         Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
         Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
         Processes.process Processes.process_exec Processes.process_guid
         Processes.process_hash Processes.process_id Processes.process_integrity_level
         Processes.process_name Processes.process_path Processes.user
         Processes.user_id Processes.vendor_product
    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_set_account_password_policy_to_unlimited_via_net_filter`
how_to_implement: 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.
references:
    - https://app.any.run/tasks/a6f2ffe2-e6e2-4396-ae2e-04ea0143f2d8/
    - https://docs.microsoft.com/en-us/troubleshoot/windows-server/networking/net-commands-on-operating-systems
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          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.
analytic_story:
    - Ransomware
    - BlackByte Ransomware
    - Crypto Stealer
    - XMRig
asset_type: Endpoint
mitre_attack_id:
    - T1489
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: tstats

| 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.action Processes.dest Processes.original_file_name
     Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
     Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
     Processes.process Processes.process_exec Processes.process_guid
     Processes.process_hash Processes.process_id Processes.process_integrity_level
     Processes.process_name Processes.process_path Processes.user
     Processes.user_id Processes.vendor_product

Stage 2: search

| `drop_dm_object_name(Processes)`

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `windows_set_account_password_policy_to_unlimited_via_net_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Processes.original_file_nameeq
  • "net1.exe" corpus 44 (sigma 19, splunk 19, elastic 6)
field:"OriginalFileName" kind:eq
Processes.processeq
  • "* /maxpwage:unlimited"
  • "* accounts *" corpus 2 (sigma 1, splunk 1)
  • "/maxpwage:49710"
field:"CommandLine" kind:eq
Processes.process_nameeq
  • "net1.exe" corpus 39 (elastic 20, splunk 19)
field:"process_name" kind:eq