WMI subscription execution (Sysmon)

Group by: _time, host
Source: github.com/anvilogic-forge/armory

Adversaries may establish persistence and elevate privileges by executing malicious content triggered by a Windows Management Instrumentation (WMI) event subscription

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1047` Windows Management Instrumentation
Persistence	`T1546.003` Event Triggered Execution: Windows Management Instrumentation Event Subscription
Privilege Escalation	`T1546.003` Event Triggered Execution: Windows Management Instrumentation Event Subscription

References

https://pentestlab.blog/2020/01/21/persistence-wmi-event-subscription/

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation

Rule body

id: '5975.18225'
title: WMI subscription execution
description: 'Adversaries may establish persistence and elevate privileges by executing
  malicious content triggered by a Windows Management Instrumentation (WMI) event
  subscription. -- Threat Actor Association: APT29, Metador, Mustang Panda (aka. Stately
  Taurus//Earth Preta/BRONZE PRESIDENT/TA416/RedDelta), TA551 - Software Association:
  BumbleBee, TargetCompany, TrailBlazer, Trickbot -- Atomics T1047 Test#7 Atomics
  T1047 Test#8 Atomics T1047 Test#9 -- While this use case can detect the above atomics,
  it is not mapped to its MITRE execution techniques due to adversaries utilizing
  this method of WMI for Privilege-Escalation and Persistence.'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` ("EventCode=1" OR "<EventID>1<")
  TERM(WmiPrvSE) | regex parent_process_name="(?i)(WmiPrvSE)" | table _time, host,
  user parent_*, process, process_*, signature_id | bin span=1s | stats values(*)
  as * by _time, host '
techniques:
- persistence:event triggered execution:windows management instrumentation event subscription
- execution:windows management instrumentation
- privilege-escalation:event triggered execution:windows management instrumentation
  event subscription
technique_id:
- T1546.003
- T1047
data_category:
- Windows Sysmon
references:
- https://pentestlab.blog/2020/01/21/persistence-wmi-event-subscription/

Stages and Predicates

Stage 1: `search`

`get_endpoint_data` `get_endpoint_data_sysmon` ("EventCode=1" OR "<EventID>1<") TERM(WmiPrvSE)

Stage 2: `regex`

| regex parent_process_name="(?i)(WmiPrvSE)"

Stage 3: `table`

| table _time, host, user parent_*, process, process_*, signature_id

Stage 4: `bucket`

| bin span=1s

Stage 5: `stats`

| stats values(*) as * by _time, host

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`parent_process_name`	regex_match	`"(?i)(WmiPrvSE)"` corpus 2 (splunk 2)	`field:"parent_process_name" kind:regex_match`

Search terms

These SPL tokens match against raw event text.

Stage	Term
1	`"EventCode=1"`
1	`"<EventID>1<"`
1	`WmiPrvSE`