detection.wiki

Detection rules › Sigma

Potentially Suspicious Self Extraction Directive File Created

Status
test
Severity
medium
Log source
product windows, category file_executable_detected
Author
Joseliyo Sanchez, @Joseliyo_Jstnk
Source
github.com/SigmaHQ/sigma

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 coverage

TacticTechniques
StealthT1218 System Binary Proxy Execution

Event coverage

ProviderEventTitle
SysmonEvent ID 29FileExecutableDetected

Rule body yaml

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.stealth
    - attack.t1218
logsource:
    product: windows
    category: file_executable_detected
detection:
    selection:
        TargetFilename|endswith: '.sed'
    condition: selection
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    TargetFilename|endswith: '.sed'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
TargetFilenameends_with
  • .sed corpus 2 (sigma 2)