Windows Process Creation: Fireball Archer installs via rundll32.exe and InstallArcherSvc

Flags rundll32.exe executions referencing InstallArcherSvc in the process command line on Windows.

FreeReviewedSigma · High · v5

Product: windows
Category: process_creation
Author: Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2017-06-03
Updated: 2026-07-31

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 flags execution events where the command line contains rundll32.exe along with InstallArcherSvc, consistent with an Archer malware installation step using Windows DLL execution. Attackers commonly use rundll32 to run code indirectly and blend execution into legitimate Windows tooling, making command-line telemetry critical. It relies on process creation events and inspection of the full command line string.

Reporting behind it

Related detections9 linkedT1218.011 — drag to rearrange

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Suspicious Scheduled Task Executing Rundll32 DLL Export by Ordinal

Malicious Renamed Rundll32 Copied to Temp via Xcopy

Suspicious rundll32 Executing DLL from ProgramData (via process_creation)

Suspicious Rundll32 Loading DLL From Public or ProgramData Path via Process Creation (via process_creation)

Malicious LSASS Credential Dump via Rundll32 Comsvcs MiniDump via Process Creation (via process_creation)

Suspicious Rundll32 Execution Without a DLL Reference via Process Creation (via process_creation)

Suspicious WebDAV Retrieval via rundll32 and davclnt.dll (via process_creation)

Windows Process Creation: Fireball Archer installs via rundll32.exe and InstallArcherSvc

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.

windows-process-creation-rundll32-exe-installarchersvc-execution-3d4aebe0

title: "Windows Process Creation: Fireball Archer installs via rundll32.exe and InstallArcherSvc"
id: 49ec03f7-b639-45a1-bd2a-032eb0ffdc75
status: test
description: This rule flags execution events where the command line contains rundll32.exe along with InstallArcherSvc, consistent with an Archer malware installation step using Windows DLL execution. Attackers commonly use rundll32 to run code indirectly and blend execution into legitimate Windows tooling, making command-line telemetry critical. It relies on process creation events and inspection of the full command line string.
references:
  - https://www.virustotal.com/en/file/9b4971349ae85aa09c0a69852ed3e626c954954a3927b3d1b6646f139b930022/analysis/
  - https://www.hybrid-analysis.com/sample/9b4971349ae85aa09c0a69852ed3e626c954954a3927b3d1b6646f139b930022?environmentId=100
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2017/Malware/Fireball/proc_creation_win_malware_fireball.yml
author: Florian Roth (Nextron Systems), Huntrule Team
date: 2017-06-03
modified: 2021-11-27
tags:
  - attack.execution
  - attack.stealth
  - attack.t1218.011
  - detection.emerging-threats
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    CommandLine|contains|all:
      - rundll32.exe
      - InstallArcherSvc
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: 3d4aebe0-6d29-45b2-a8a4-3dfde586a26d
    type: derived

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