defense_evasion_disable_nla.toml

[metadata]
creation_date = "2023/08/25"
integration = ["endpoint"]
maturity = "production"
min_stack_comments = "New fields added: required_fields, related_integrations, setup"
min_stack_version = "8.3.0"
updated_date = "2023/10/09"
bypass_bbr_timing = true

[rule]
author = ["Elastic"]
description = """
Identifies the attempt to disable Network-Level Authentication (NLA) via registry modification. Network Level Authentication (NLA) is a feature on Windows
that provides an extra layer of security for Remote Desktop (RDP) connections, as it requires users to authenticate
before allowing a full RDP session. Attackers can disable NLA to enable persistence methods that require access to the
Windows sign-in screen without authenticating, such as Accessibility Features persistence methods, like Sticky Keys.
"""
from = "now-9m"
index = ["logs-endpoint.events.*", "endgame-*"]
language = "eql"
license = "Elastic License v2"
name = "Network-Level Authentication (NLA) Disabled"
references = [
    "https://www.microsoft.com/en-us/security/blog/2023/08/24/flax-typhoon-using-legitimate-software-to-quietly-access-taiwanese-organizations/",
]
risk_score = 21
rule_id = "db65f5ba-d1ef-4944-b9e8-7e51060c2b42"
severity = "low"
tags = ["Domain: Endpoint", "OS: Windows", "Use Case: Threat Detection", "Tactic: Defense Evasion", "Data Source: Elastic Defend", "Data Source: Elastic Endgame", "Rule Type: BBR"]
timestamp_override = "event.ingested"
building_block_type = "default"
type = "eql"

query = '''
registry where host.os.type == "windows" and event.action != "deletion" and
  registry.path :
       ("HKLM\\SYSTEM\\ControlSet*\\Control\\Terminal Server\\WinStations\\RDP-Tcp\\UserAuthentication", 
        "\\REGISTRY\\MACHINE\\SYSTEM\\*ControlSet*\\Control\\Terminal Server\\WinStations\\RDP-Tcp\\UserAuthentication" ) and
  registry.data.strings : "0"
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1112"
name = "Modify Registry"
reference = "https://attack.mitre.org/techniques/T1112/"

[[rule.threat.technique]]
id = "T1562"
name = "Impair Defenses"
reference = "https://attack.mitre.org/techniques/T1562/"


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