Kapeka backdoor execution via rundll32.exe with export ordinal #1 and -d on Windows

Flags rundll32.exe command lines launching a Kapeka payload from ProgramData/AppData Local using export ordinal #1 with "-d".

FreeReviewedSigma · High · v5

Product: windows
Category: process_creation
Author: Swachchhanda Shrawan Poudel, Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2024-07-03
Updated: 2026-07-31

Analysis Detection

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1218.011Rundll32
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects a Kapeka backdoor execution pattern where rundll32.exe is used to launch a backdoor payload stored under ProgramData or AppData\Local. The command line includes the backdoor module marker '.wll', invokes export ordinal '#1', and passes the '-d' argument. This matters because abusing rundll32 with ordinal execution helps attackers hide the real payload while blending into legitimate Windows binary usage. The detection relies on Windows process creation telemetry with the image path and full command line content.

Reporting behind it

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Malicious Rundll32 DllRegisterServer Execution From a User-Writable Path (via process_creation)

IMEEX Framework DLL Execution via Rundll32 Loading imaadp (via process_creation)

Suspicious Persistence via pcalua Launching rundll32 Control_RunDLL

Suspicious Rundll32 Executing DLL Start Export With Control Flags

Suspicious Rundll32 Execution of Timestamp-Named DLL

Suspicious Rundll32 Loading DLL from LocalAppData with Short Export (via process_creation)

Kapeka backdoor execution via rundll32.exe with export ordinal #1 and -d on Windows

Pivot detection · T1218.011 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
v1
No 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.

kapeka-backdoor-execution-via-rundll32-exe-with-ordinal-export-1-and-d-argument--e98f741c

title: "Kapeka backdoor execution via rundll32.exe with export ordinal #1 and -d on Windows"
id: 9ce22e86-4c93-46a6-b3a7-848ada87c538
status: test
description: This rule detects a Kapeka backdoor execution pattern where rundll32.exe is used to launch a backdoor payload stored under ProgramData or AppData\Local. The command line includes the backdoor module marker '.wll', invokes export ordinal '#1', and passes the '-d' argument. This matters because abusing rundll32 with ordinal execution helps attackers hide the real payload while blending into legitimate Windows binary usage. The detection relies on Windows process creation telemetry with the image path and full command line content.
references:
  - https://labs.withsecure.com/publications/kapeka
  - https://app.any.run/tasks/1efb3ed4-cc0f-4690-a0ed-24516809bc72/
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2024/Malware/kapeka/proc_creation_win_malware_kapeka_backdoor_rundll32_execution.yml
author: Swachchhanda Shrawan Poudel, Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2024-07-03
tags:
  - attack.stealth
  - attack.t1218.011
  - detection.emerging-threats
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    - Image|endswith: \rundll32.exe
    - OriginalFileName: RUNDLL32.EXE
  selection_backdoor_path:
    CommandLine|contains:
      - :\ProgramData
      - \AppData\Local
  selection_backdoor_exec_1:
    CommandLine|contains|all:
      - .wll
      - "#1"
      - " -d"
  selection_backdoor_exec_2:
    CommandLine|contains: .wll
    CommandLine|endswith: "#1"
  condition: selection_img and selection_backdoor_path and 1 of selection_backdoor_exec_*
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: e98f741c-6a5b-4c83-bc2a-1f4e58d07b12
    type: derived

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