Detection rules › Sigma
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.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Privilege Escalation | T1055 Process Injection |
| Stealth | T1055 Process Injection |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
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
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
ParentImage|endswith:
- '\chrome.exe'
- '\firefox.exe'
- '\msedge.exe'
Image|endswith: '\rundll32.exe'
CommandLine|endswith: '\rundll32.exe'
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.
| Field | Kind | Values |
|---|---|---|
CommandLine | ends_with |
|
Image | ends_with |
|
ParentImage | ends_with |
|