Windows Recent Files Shortcut Points to ISO/IMG/VHD Mount Images

Flags Windows Recent Items entries that reference ISO/IMG/VHD/VHDX mount shortcuts.

FreeReviewedSigma · Medium · v2
Product
windows
Category
file_event
Author
Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2022-02-11
Updated
2026-07-31
title: Windows Recent Files Shortcut Points to ISO/IMG/VHD Mount Images
id: 94401ccb-501c-435d-8788-eab4e642214f
status: test
description: Identifies Windows file events where a Recent folder shortcut target ends with .iso.lnk, .img.lnk, .vhd.lnk, or .vhdx.lnk. This pattern can indicate that an ISO/IMG/VHD container is being referenced through Recent files, a technique attackers may use during phishing or initial access. The rule relies on telemetry that captures the created file name/path for shortcuts under \\Microsoft\\Windows\\Recent\\.
references:
  - https://www.microsoft.com/security/blog/2021/05/27/new-sophisticated-email-based-attack-from-nobelium/
  - https://www.trendmicro.com/vinfo/us/security/news/cybercrime-and-digital-threats/malicious-spam-campaign-uses-iso-image-files-to-deliver-lokibot-and-nanocore
  - https://blog.emsisoft.com/en/32373/beware-new-wave-of-malware-spreads-via-iso-file-email-attachments/
  - https://insights.sei.cmu.edu/blog/the-dangers-of-vhd-and-vhdx-files/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/file/file_event/file_event_win_iso_file_recent.yml
author: Florian Roth (Nextron Systems), Huntrule Team
date: 2022-02-11
tags:
  - attack.initial-access
  - attack.t1566.001
logsource:
  product: windows
  category: file_event
detection:
  selection:
    TargetFilename|endswith:
      - .iso.lnk
      - .img.lnk
      - .vhd.lnk
      - .vhdx.lnk
    TargetFilename|contains: \Microsoft\Windows\Recent\
  condition: selection
falsepositives:
  - Cases in which a user mounts an image file for legitimate reasons
level: medium
license: DRL-1.1
related:
  - id: 4358e5a5-7542-4dcb-b9f3-87667371839b
    type: derived