Injected Browser Process Spawning Rundll32 - GuLoader Activity

Detects the execution of installed GuLoader malware on the host. GuLoader is initiating network connections via the rundll32.exe process that is spawned via a browser parent(injected) process.

title: Injected Browser Process Spawning Rundll32 - GuLoader Activity
id: 89e1490f-1a3e-452a-bbb8-b68a5f58072f
status: test
description: |
    Detects the execution of installed GuLoader malware on the host.
    GuLoader is initiating network connections via the rundll32.exe process that is spawned via a browser parent(injected) process.
references:
    - Internal Research
author: '@kostastsale'
date: 2023-08-07
tags:
    - attack.privilege-escalation
    - attack.stealth
    - attack.t1055
    - detection.emerging-threats
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith:
            - '\chrome.exe'
            - '\firefox.exe'
            - '\msedge.exe'
        Image|endswith: '\rundll32.exe'
        CommandLine|endswith: '\rundll32.exe'
    condition: selection
falsepositives:
    - Unlikely
level: high

• T1055Process Injection

• Internal Research