Windows: Alerts on Creation of .sed Self-Extraction Directive File

Flags creation of newly created .sed directive files on Windows, which can be used for self-extracting package abuse.

FreeReviewedSigma · Medium · v2

Product: windows
Category: file_executable_detected
Author: Joseliyo Sanchez, @Joseliyo_Jstnk (SigmaHQ), DRL 1.1
Published: 2024-02-05
Updated: 2026-07-31

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1218System Binary Proxy Execution
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags when a new file is created with a filename ending in “.sed”, which are Self Extraction Directive files. Attackers may abuse Windows packaging workflows to place directives into unexpected files, sometimes embedding PE content associated with the directive. Telemetry required is Windows file creation/executable file creation events that include the target filename.

Reporting behind it

Related detections9 linkedT1218 — drag to rearrange

Suspicious Cabinet Extraction of Masqueraded vstm Archive via extrac32

Malicious DLL Execution via Wuauclt Update Handler (via process_creation)

Malicious aspnet_compiler.exe Injection Host Spawned by PowerShell via process_creation

Malicious regsvcs LOLBin Loading Ransomware DLL from UNC Path

Suspicious RegAsm or RegSvcs Spawned by Script Host (via process_creation)

Suspicious Extexport DLL Side-Loading Execution

Malicious ClickFix Execution Chain Spawning MSHTA via Pcalua on EtherRAT Infection

Suspicious TALONITE Certutil LOLBIN Decode and Download Abuse (via process_creation)

Suspicious Renamed git Binary gcmd.exe Execution (via process_creation)

Windows: Alerts on Creation of .sed Self-Extraction Directive File

Pivot detection · T1218 · 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-alert-on-new-sed-file-creation-consistent-with-self-extraction-directive-ab90dab8

title: "Windows: Alerts on Creation of .sed Self-Extraction Directive File"
id: eac7304c-fd27-47ae-9d8a-c87508df8830
related:
  - id: 760e75d8-c3b5-409b-a9bf-6130b4c4603f
    type: derived
  - id: ab90dab8-c7da-4010-9193-563528cfa347
    type: derived
status: test
description: This rule flags when a new file is created with a filename ending in “.sed”, which are Self Extraction Directive files. Attackers may abuse Windows packaging workflows to place directives into unexpected files, sometimes embedding PE content associated with the directive. Telemetry required is Windows file creation/executable file creation events that include the target filename.
references:
  - https://strontic.github.io/xcyclopedia/library/iexpress.exe-D594B2A33EFAFD0EABF09E3FDC05FCEA.html
  - https://en.wikipedia.org/wiki/IExpress
  - https://www.virustotal.com/gui/file/602f4ae507fa8de57ada079adff25a6c2a899bd25cd092d0af7e62cdb619c93c/behavior
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/file/file_executable_detected/file_executable_detected_win_susp_embeded_sed_file.yml
author: Joseliyo Sanchez, @Joseliyo_Jstnk, Huntrule Team
date: 2024-02-05
tags:
  - attack.stealth
  - attack.t1218
logsource:
  product: windows
  category: file_executable_detected
detection:
  selection:
    TargetFilename|endswith: .sed
  condition: selection
falsepositives:
  - Unknown
level: medium
license: DRL-1.1

Convert

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

SplunkSPL