AMSI Bypass via COM Registry Modification

[rule]
description = """
Identifies attempts to disable the Microsoft Antimalware Scan Interface via registry modification. This may indicate an
attempt to tamper with certain Windows native protections.
"""
id = "0a3152e5-122f-4145-a107-7ec789b9b1a3"
license = "Elastic License v2"
name = "AMSI Bypass via COM Registry Modification"
os_list = ["windows"]
version = "1.0.4"

query = '''
registry where event.action == "modification" and  
 registry.path : "HKEY_USERS\\*_Classes\\CLSID\\{fdb00e52-a214-4aa1-8fba-4357bb0072ec}\\InProcServer*" and 
 not registry.data.strings : ("?:\\Windows\\System32\\amsi.dll", "?:\\Windows\\SysWOW64\\amsi.dll")
'''

min_endpoint_version = "7.16.0"
[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 0

[[optional_actions]]
action = "rollback"
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 = "7.16.0"