QoS Policy Group Policy Registry Overwrite via WMI

[rule]
description = """
Identifies the overwrite of the machine Group Policy registry file Registry.pol by WmiPrvSE.exe with a call stack
indicating QoS WMI policy configuration through gpedit.dll and qoswmi.dll. Tools such as EDRChoker abuse Policy-based
Quality of Service to throttle Endpoint Detection and Response agents by persisting bandwidth caps in Group Policy,
causing telemetry uploads to time out.
"""
id = "0c206fcc-ad17-4aee-84df-767ab74c28a1"
license = "Elastic License v2"
name = "QoS Policy Group Policy Registry Overwrite via WMI"
os_list = ["windows"]
reference = ["https://github.com/TwoSevenOneT/EDRChoker"]
version = "1.0.1"

query = '''
file where event.action == "overwrite" and
  file.path : "?:\\Windows\\System32\\GroupPolicy\\Machine\\Registry.pol" and
  process.name : "WmiPrvSE.exe" and
  Effective_process.name != null and
  process.thread.Ext.call_stack_summary like "ntdll.dll*|kernelbase.dll|gpedit.dll|qoswmi.dll|*" and 
  not (user.id == "S-1-5-18" and Effective_process.name : "powershell.exe")
'''

min_endpoint_version = "8.7.0"
optional_actions = []
[[actions]]
action = "kill_process"
field = "Effective_process.entity_id"
state = 0

[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 0

[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1562"
name = "Impair Defenses"
reference = "https://attack.mitre.org/techniques/T1562/"
[[threat.technique.subtechnique]]
id = "T1562.001"
name = "Disable or Modify Tools"
reference = "https://attack.mitre.org/techniques/T1562/001/"



[threat.tactic]
id = "TA0005"
name = "Defense Evasion"
reference = "https://attack.mitre.org/tactics/TA0005/"

[internal]
min_endpoint_version = "8.7.0"