Detection rules › Sigma

Potential Privilege Escalation Attempt Via .Exe.Local Technique

Status
test
Severity
high
Log source
product windows, category file_event
Author
Nasreddine Bencherchali (Nextron Systems), Subhash P (@pbssubhash)
Source
github.com/SigmaHQ/sigma

Detects potential privilege escalation attempt via the creation of the "*.Exe.Local" folder inside the "System32" directory in order to sideload "comctl32.dll"

MITRE ATT&CK coverage

TacticTechniques
PersistenceNo specific technique
Privilege EscalationNo specific technique
StealthNo specific technique

Event coverage

ProviderEventTitle
SysmonEvent ID 11FileCreate

Rule body yaml

title: Potential Privilege Escalation Attempt Via .Exe.Local Technique
id: 07a99744-56ac-40d2-97b7-2095967b0e03
status: test
description: Detects potential privilege escalation attempt via the creation of the "*.Exe.Local" folder inside the "System32" directory in order to sideload "comctl32.dll"
references:
    - https://github.com/binderlabs/DirCreate2System
    - https://github.com/sailay1996/awesome_windows_logical_bugs/blob/60cbb23a801f4c3195deac1cc46df27c225c3d07/dir_create2system.txt
author: Nasreddine Bencherchali (Nextron Systems), Subhash P (@pbssubhash)
date: 2022-12-16
modified: 2022-12-19
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.stealth
logsource:
    category: file_event
    product: windows
detection:
    selection:
        TargetFilename|startswith:
            - 'C:\Windows\System32\logonUI.exe.local'
            - 'C:\Windows\System32\werFault.exe.local'
            - 'C:\Windows\System32\consent.exe.local'
            - 'C:\Windows\System32\narrator.exe.local'
            - 'C:\Windows\System32\wermgr.exe.local'
        TargetFilename|endswith: '\comctl32.dll'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    TargetFilename|startswith:
        - 'C:\Windows\System32\logonUI.exe.local'
        - 'C:\Windows\System32\werFault.exe.local'
        - 'C:\Windows\System32\consent.exe.local'
        - 'C:\Windows\System32\narrator.exe.local'
        - 'C:\Windows\System32\wermgr.exe.local'
    TargetFilename|endswith: '\comctl32.dll'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
TargetFilenameends_with
  • \comctl32.dll corpus 2 (sigma 2)
TargetFilenamestarts_with
  • C:\Windows\System32\consent.exe.local
  • C:\Windows\System32\logonUI.exe.local
  • C:\Windows\System32\narrator.exe.local
  • C:\Windows\System32\werFault.exe.local
  • C:\Windows\System32\wermgr.exe.local