Windows Network Connections Initiated by Eqnedt32.EXE

Identifies outbound network connections started by eqnedt32.exe on Windows.

FreeReviewedSigma · High · v2

Product: windows
Category: network_connection
Author: Max Altgelt (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2022-04-14
Updated: 2026-07-31

ATT&CK techniques

Execution

Recon
Resource Dev
Initial Access
Execution
- T1203Exploitation for Client Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags outbound or inbound network connections where the initiating process image ends with eqnedt32.exe (Microsoft Equation Editor). Attackers may abuse Equation Editor to execute malicious code that communicates over the network. The detection relies on Windows network connection telemetry that includes the connecting process image path.

Reporting behind it

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Antivirus signatures matching APT malware naming patterns

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Malicious Microsoft Word Spawning Anomalous Child Process via CVE-2023-36884 (via process_creation)

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Malicious Equation Editor Child Process Execution via process_creation

Windows Network Connections Initiated by Eqnedt32.EXE

Pivot detection · T1203 · 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-network-connections-from-eqnedt32-exe-equation-editor-a66bc059

title: Windows Network Connections Initiated by Eqnedt32.EXE
id: 6ccb8bf8-4937-41aa-a052-4488d9b2c5f2
status: test
description: This rule flags outbound or inbound network connections where the initiating process image ends with eqnedt32.exe (Microsoft Equation Editor). Attackers may abuse Equation Editor to execute malicious code that communicates over the network. The detection relies on Windows network connection telemetry that includes the connecting process image path.
references:
  - https://twitter.com/forensicitguy/status/1513538712986079238
  - https://forensicitguy.github.io/xloader-formbook-velvetsweatshop-spreadsheet/
  - https://news.sophos.com/en-us/2019/07/18/a-new-equation-editor-exploit-goes-commercial-as-maldoc-attacks-using-it-spike/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/network_connection/net_connection_win_eqnedt.yml
author: Max Altgelt (Nextron Systems), Huntrule Team
date: 2022-04-14
modified: 2024-05-31
tags:
  - attack.execution
  - attack.t1203
logsource:
  category: network_connection
  product: windows
detection:
  selection:
    Image|endswith: \eqnedt32.exe
  condition: selection
falsepositives:
  - Unlikely
level: high
license: DRL-1.1
related:
  - id: a66bc059-c370-472c-a0d7-f8fd1bf9d583
    type: derived

Convert

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

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