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name, description, domain, subdomain, tags, version, author, license, mitre_attack, d3fend, references
name description domain subdomain tags version author license mitre_attack d3fend references
analyzing-malicious-iso-and-container-files Analyzes malicious ISO, IMG, VHD, and similar container files used to smuggle payloads past email and mark-of-the-web defenses by enumerating contents and flagging hidden executables, LNKs, and scripts. Activates for requests to analyze a malicious ISO/IMG, inspect a container delivery file, or find payloads hidden inside a disk image attachment. cybersecurity malware-analysis
malware-analysis
iso
container
delivery
mark-of-the-web
1.0.0 analyst-ai-pack Apache-2.0
T1553.005
T1204.002
T1027
D3-FCR
D3-FA
MITRE ATT&CK T1553.005 Mark-of-the-Web Bypass — https://attack.mitre.org/techniques/T1553/005/
ISO 9660 file system — https://wiki.osdev.org/ISO_9660

Analyzing Malicious ISO and Container Files

When to Use

  • You have an ISO/IMG/VHD attachment suspected of smuggling a payload (LNK + hidden DLL/EXE/script) past MOTW and scanners.
  • You need to enumerate contents and flag hidden/executable entries without mounting the image.

Do not use mounting/auto-run to inspect — that can trigger the lure. Parse the container's directory records statically.

Prerequisites

  • The container file (read inertly). Optional: pycdlib for full ISO parsing (the script falls back to signature/string carving if absent).

Safety & Handling

  • Never mount or open the container interactively; carve statically. Defang any URLs found.

Workflow

Step 1: Identify the container type

python scripts/analyst.py inspect sample.iso

Detects ISO 9660 (CD001), UDF, FAT/VHD signatures and reports the format.

Step 2: Enumerate entries and flag payloads

Lists embedded file signatures (MZ, PK, LNK \x4C\x00\x00\x00, script headers) and flags hidden/executable/decoy entries.

Step 3: Assess the lure chain

A typical chain is a visible LNK pointing at a hidden DLL/EXE/script in the same image — document the relationship.

Step 4: Extract and route

Carve the hidden payload and route it to the appropriate analysis workflow; defang URLs.

Validation

  • The container format is identified by signature.
  • Hidden executables/LNKs/scripts are enumerated with offsets.
  • The lure→payload relationship is documented.

Pitfalls

  • Mounting the image and triggering the lure.
  • Missing payloads in less-common container formats (VHDX, UDF) without the right parser.
  • Overlooking hidden-attribute files that the file manager would not show.

References