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Potentially Suspicious Self Extraction Directive File Created

Detects the creation of a binary file with the ".sed" extension. The ".sed" extension stand for Self Extraction Directive files. These files are used by the "iexpress.exe" utility in order to create self extracting packages. Attackers were seen abusing this utility and creating PE files with embedded ".sed" entries. Usually ".sed" files are simple ini files and not PE binaries.

MITRE ATT&CK

T1218

defense-evasion

Detection Query

selection:
  TargetFilename|endswith: .sed
condition: selection

Author

Joseliyo Sanchez, @Joseliyo_Jstnk

Created

2024-02-05

Data Sources

windowsfile_executable_detected

Platforms

windows

References

Tags

attack.defense-evasionattack.t1218

Raw Content

title: Potentially Suspicious Self Extraction Directive File Created
id: ab90dab8-c7da-4010-9193-563528cfa347
related:
    - id: 760e75d8-c3b5-409b-a9bf-6130b4c4603f
      type: derived
status: test
description: |
    Detects the creation of a binary file with the ".sed" extension. The ".sed" extension stand for Self Extraction Directive files.
    These files are used by the "iexpress.exe" utility in order to create self extracting packages.
    Attackers were seen abusing this utility and creating PE files with embedded ".sed" entries.
    Usually ".sed" files are simple ini files and not PE binaries.
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
author: Joseliyo Sanchez, @Joseliyo_Jstnk
date: 2024-02-05
tags:
    - attack.defense-evasion
    - attack.t1218
logsource:
    product: windows
    category: file_executable_detected
detection:
    selection:
        TargetFilename|endswith: '.sed'
    condition: selection
falsepositives:
    - Unknown
level: medium