Windows image load and execution of unsigned Thor scanner (thor.exe/thor64.exe)

Alerts on thor.exe/thor64.exe image loads on Windows where the Authenticode signature is missing or not from Nextron Systems.

FreeReviewedSigma · High · v2

Product: windows
Category: image_load
Author: Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2023-10-29
Updated: 2026-07-31

Analysis Detection

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1574.001DLL
Persistence
- T1574.001DLL
Priv Esc
- T1574.001DLL
Defense Evasion
- T1574.001DLL
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags when a Windows process loads and executes a binary named thor.exe or thor64.exe that is not signed as valid by Nextron Systems. Attackers may use unsigned or differently signed executables with trusted names to evade trust checks and blend into normal tooling. The detection relies on image load telemetry and signature metadata (Signed, SignatureStatus, and Signature) tied to the loaded executable path.

Reporting behind it

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Windows image load and execution of unsigned Thor scanner (thor.exe/thor64.exe)

Pivot detection · T1574.001 · 9 related

Changelog

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-image-load-executes-unsigned-thor-scanner-binaries-ea5c131b

title: Windows image load and execution of unsigned Thor scanner (thor.exe/thor64.exe)
id: 737ec172-2b11-4c9f-bfa7-8c6eeba37ca4
status: stable
description: This rule flags when a Windows process loads and executes a binary named thor.exe or thor64.exe that is not signed as valid by Nextron Systems. Attackers may use unsigned or differently signed executables with trusted names to evade trust checks and blend into normal tooling. The detection relies on image load telemetry and signature metadata (Signed, SignatureStatus, and Signature) tied to the loaded executable path.
references:
  - Internal Research
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/image_load/image_load_thor_unsigned_execution.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2023-10-29
tags:
  - attack.privilege-escalation
  - attack.persistence
  - attack.execution
  - attack.stealth
  - attack.t1574.001
logsource:
  category: image_load
  product: windows
detection:
  selection:
    Image|endswith:
      - \thor.exe
      - \thor64.exe
    ImageLoaded|endswith:
      - \thor.exe
      - \thor64.exe
  filter_main:
    Signed: "true"
    SignatureStatus: valid
    Signature: Nextron Systems GmbH
  condition: selection and not filter_main
falsepositives:
  - Other legitimate binaries named "thor.exe" that aren't published by Nextron Systems
level: high
license: DRL-1.1
related:
  - id: ea5c131b-380d-49f9-aeb3-920694da4d4b
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

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