Detection rules › Elastic

UAC Bypass Attempt via WOW64 Logger DLL Side-Loading

Time window
1m
Sequence by
process.entity_id, process.parent.entity_id
Source
github.com/elastic/protections-artifacts

Identifies attempts to bypass User Account Control (UAC) via WoW64 logger DLL side-loading. Attackers may attempt to bypass UAC to stealthily execute code with elevated permissions.

MITRE ATT&CK coverage

Rule body

[rule]
description = """
Identifies attempts to bypass User Account Control (UAC) via WoW64 logger DLL side-loading. Attackers may attempt to
bypass UAC to stealthily execute code with elevated permissions.
"""
id = "28a39a43-e850-4941-8605-ffa23dcfd25a"
license = "Elastic License v2"
name = "UAC Bypass Attempt via WOW64 Logger DLL Side-Loading"
os_list = ["windows"]
reference = ["https://github.com/hfiref0x/UACME", "http://waleedassar.blogspot.com/2013/01/wow64logdll.html"]
version = "1.0.32"

query = '''
sequence with maxspan=60s
 [library where dll.name : "wow64log.dll" and
  not (dll.code_signature.subject_name : "Microsoft *" and dll.code_signature.trusted == true)
 ] by process.entity_id
 [process where event.action == "start" and
  process.Ext.token.integrity_level_name : ("high", "system") and
  not process.executable :
           ("?:\\Windows\\System32\\WerFault.exe",
            "?:\\Windows\\SysWOW64\\WerFault.exe",
            "?:\\Windows\\System32\\wermgr.exe",
            "?:\\Windows\\SysWOW64\\wermgr.exe",
            "?:\\Windows\\System32\\conhost.exe",
            "?:\\Windows\\SysWOW64\\conhost.exe")] by process.parent.entity_id
'''

min_endpoint_version = "7.15.0"
[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 1

[[optional_actions]]
action = "rollback"
field = "process.entity_id"
state = 1

[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1548"
name = "Abuse Elevation Control Mechanism"
reference = "https://attack.mitre.org/techniques/T1548/"
[[threat.technique.subtechnique]]
id = "T1548.002"
name = "Bypass User Account Control"
reference = "https://attack.mitre.org/techniques/T1548/002/"



[threat.tactic]
id = "TA0004"
name = "Privilege Escalation"
reference = "https://attack.mitre.org/tactics/TA0004/"
[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1574"
name = "Hijack Execution Flow"
reference = "https://attack.mitre.org/techniques/T1574/"
[[threat.technique.subtechnique]]
id = "T1574.001"
name = "DLL"
reference = "https://attack.mitre.org/techniques/T1574/001/"



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

[internal]
min_endpoint_version = "7.15.0"

Stages and Predicates

Ordered sequence: each step below must occur in order within 1m, correlated by process.entity_id, process.parent.entity_id.

Stage 1: library

[library where dll.name : "wow64log.dll" and
  not (dll.code_signature.subject_name : "Microsoft *" and dll.code_signature.trusted == true)
 ] by process.entity_id

Stage 2: process

[process where event.action == "start" and
  process.Ext.token.integrity_level_name : ("high", "system") and
  not process.executable :
           ("?:\\Windows\\System32\\WerFault.exe",
            "?:\\Windows\\SysWOW64\\WerFault.exe",
            "?:\\Windows\\System32\\wermgr.exe",
            "?:\\Windows\\SysWOW64\\wermgr.exe",
            "?:\\Windows\\System32\\conhost.exe",
            "?:\\Windows\\SysWOW64\\conhost.exe")] by process.parent.entity_id

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
dll.code_signature.subject_namestarts_withMicrosoft excludes:dll.code_signature.subject_name field:"dll.code_signature.subject_name" value:"Microsoft "
dll.code_signature.trustedeqtrueexcludes:dll.code_signature.trusted field:"dll.code_signature.trusted" value:"true"
process.executableeq?:\Windows\System32\WerFault.exe, ?:\Windows\SysWOW64\WerFault.exe, ?:\Windows\System32\wermgr.exe, ?:\Windows\SysWOW64\wermgr.exe, ?:\Windows\System32\conhost.exe, ?:\Windows\SysWOW64\conhost.exeexcludes:process.executable

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
dll.namewildcard
  • wow64log.dll corpus 3 (elastic 3)
field:"dll.name" kind:wildcard value:"wow64log.dll"
event.actioneq
  • start corpus 391 (elastic 391)
field:"EventType" kind:eq value:"start"
process.Ext.token.integrity_level_namewildcard
  • high corpus 22 (elastic 22)
  • system corpus 14 (elastic 14)
field:"process.Ext.token.integrity_level_name" kind:wildcard