Detection rules › Sigma

DLL Search Order Hijackig Via Additional Space in Path

Status
test
Severity
high
Log source
category file_event, product windows
Author
frack113, Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects when an attacker create a similar folder structure to windows system folders such as (Windows, Program Files...) but with a space in order to trick DLL load search order and perform a "DLL Search Order Hijacking" attack

MITRE ATT&CK coverage

Telemetry coverage

ProviderRecord / event type
SysmonEvent ID 11: FileCreate

Rule body

title: DLL Search Order Hijackig Via Additional Space in Path
id: b6f91281-20aa-446a-b986-38a92813a18f
status: test
description: |
    Detects when an attacker create a similar folder structure to windows system folders such as (Windows, Program Files...)
    but with a space in order to trick DLL load search order and perform a "DLL Search Order Hijacking" attack
references:
    - https://twitter.com/cyb3rops/status/1552932770464292864
    - https://www.wietzebeukema.nl/blog/hijacking-dlls-in-windows
author: frack113, Nasreddine Bencherchali (Nextron Systems)
date: 2022-07-30
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: file_event
    product: windows
detection:
    selection:
        TargetFilename|startswith:
            - 'C:\Windows \'
            - 'C:\Program Files \'
            - 'C:\Program Files (x86) \'
        TargetFilename|endswith: '.dll'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    TargetFilename|startswith:
        - 'C:\Windows \'
        - 'C:\Program Files \'
        - 'C:\Program Files (x86) \'
    TargetFilename|endswith: '.dll'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
TargetFilenameends_with
  • .dll corpus 24 (sigma 24)
field:"TargetFilename" kind:ends_with value:".dll"
TargetFilenamestarts_with
  • C:\Program Files (x86) \
  • C:\Program Files \
  • C:\Windows \
field:"TargetFilename" kind:starts_with