Windows TAIDOOR RAT DLL Load via rundll32 Command Line
Detects Windows process creation command lines consistent with TAIDOOR RAT DLL loading through rundll32.exe.
- Product
- windows
- Category
- process_creation
- Author
- Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
- Published
- 2020-07-30
- Updated
- 2026-07-31
ATT&CK techniques
Priv Esc → Defense EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule identifies Windows process creation where the command line suggests DLL execution consistent with TAIDOOR RAT-style loading, either by matching specific DLL/MyStart parameters or by combining a MyStart-ending command line with rundll32.exe. Such behavior matters because it indicates an attacker using a DLL entry point to run code while blending into legitimate execution patterns. The detection relies on process creation telemetry, specifically the CommandLine field content.
Reporting behind it
Changelog
v5- v5Candidate ingested via manual entry.2026-07-31
- v4Candidate ingested via manual entry.2026-07-31
- v3Candidate ingested via manual entry.2026-07-31
- v2Candidate ingested via manual entry.2026-07-31
- v1No changelog recorded for this version.2026-07-30
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
title: Windows TAIDOOR RAT DLL Load via rundll32 Command Line
id: f7bced47-ca4a-4f5b-806b-ba8d4971157c
status: test
description: This rule identifies Windows process creation where the command line suggests DLL execution consistent with TAIDOOR RAT-style loading, either by matching specific DLL/MyStart parameters or by combining a MyStart-ending command line with rundll32.exe. Such behavior matters because it indicates an attacker using a DLL entry point to run code while blending into legitimate execution patterns. The detection relies on process creation telemetry, specifically the CommandLine field content.
references:
- https://us-cert.cisa.gov/ncas/analysis-reports/ar20-216a
- https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2020/TA/TAIDOOR-RAT/proc_creation_win_apt_taidoor.yml
author: Florian Roth (Nextron Systems), Huntrule Team
date: 2020-07-30
modified: 2021-11-27
tags:
- attack.privilege-escalation
- attack.execution
- attack.stealth
- attack.t1055.001
- detection.emerging-threats
logsource:
category: process_creation
product: windows
detection:
selection1:
CommandLine|contains:
- dll,MyStart
- dll MyStart
selection2a:
CommandLine|endswith: " MyStart"
selection2b:
CommandLine|contains: rundll32.exe
condition: selection1 or ( selection2a and selection2b )
falsepositives:
- Unknown
level: high
license: DRL-1.1
related:
- id: d1aa3382-abab-446f-96ea-4de52908210b
type: derived