Potential Protected Process DLL Injection via RPC

Source: github.com/elastic/protections-artifacts

Identifies when a process running as protected process loads an unsigned DLL. This may indicate an attempt to bypass Process Protection and inject malicious code.

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1211` Exploitation for Stealth `T1574` Hijack Execution Flow

Rule body

[rule]
description = """
Identifies when a process running as protected process loads an unsigned DLL. This may indicate an attempt to bypass
Process Protection and inject malicious code.
"""
id = "e8ed06c7-3a70-40a7-85a5-4fc6a2203fce"
license = "Elastic License v2"
name = "Potential Protected Process DLL Injection via RPC"
os_list = ["windows"]
reference = [
    "https://www.elastic.co/blog/protecting-windows-protected-processes",
    "https://github.com/Slowerzs/PPLSystem/tree/main",
]
version = "1.0.3"

query = '''
library where dll.Ext.defense_evasions : "Process Tampering: Code integrity violation" and
  process.thread.Ext.call_stack_summary : "ntdll.dll|rpcrt4.dll|combase.dll|*"
'''

min_endpoint_version = "8.7.0"
[[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 = "T1211"
name = "Exploitation for Defense Evasion"
reference = "https://attack.mitre.org/techniques/T1211/"

[[threat.technique]]
id = "T1574"
name = "Hijack Execution Flow"
reference = "https://attack.mitre.org/techniques/T1574/"


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

[internal]
min_endpoint_version = "8.7.0"

Stages and Predicates

Stage 1: `library`

library where dll.Ext.defense_evasions : "Process Tampering: Code integrity violation" and
  process.thread.Ext.call_stack_summary : "ntdll.dll|rpcrt4.dll|combase.dll|*"

Indicators

These rows show field, operator, and value matches.