t1036-008-masquerade-file-type

name	T1036.008_masquerade-file-type
description	Adversaries may masquerade malicious payloads as legitimate files through changes to the payload's formatting, including the file’s signature, extension, icon, and contents.
category	configuration
version	18.1
author	cyberstrike-official
tags	["mitre-attack","enterprise","t1036.008","defense-evasion","linux","macos","windows","sub-technique"]
technique_id	T1036.008
tactic	defense-evasion
all_tactics	["defense-evasion"]
platforms	["Linux","macOS","Windows"]
mitre_url	https://attack.mitre.org/techniques/T1036/008
tech_stack	["linux","macos","windows"]
cwe_ids	["CWE-693"]
chains_with	["T1036","T1036.001","T1036.002","T1036.003","T1036.004","T1036.005","T1036.006","T1036.007","T1036.009","T1036.010","T1036.011","T1036.012"]
prerequisites	["T1036"]
severity_boost	{"T1036":"Chain with T1036 for deeper attack path","T1036.001":"Chain with T1036.001 for deeper attack path","T1036.002":"Chain with T1036.002 for deeper attack path"}

T1036.008 Masquerade File Type

Sub-technique of: T1036

High-Level Description

Adversaries may masquerade malicious payloads as legitimate files through changes to the payload's formatting, including the file’s signature, extension, icon, and contents. Various file types have a typical standard format, including how they are encoded and organized. For example, a file’s signature (also known as header or magic bytes) is the beginning bytes of a file and is often used to identify the file’s type. For example, the header of a JPEG file, is 0xFF 0xD8 and the file extension is either .JPE, .JPEG or .JPG.

Adversaries may edit the header’s hex code and/or the file extension of a malicious payload in order to bypass file validation checks and/or input sanitization. This behavior is commonly used when payload files are transferred (e.g., Ingress Tool Transfer) and stored (e.g., Upload Malware) so that adversaries may move their malware without triggering detections.

Common non-executable file types and extensions, such as text files (.txt) and image files (.jpg, .gif, etc.) may be typically treated as benign. Based on this, adversaries may use a file extension to disguise malware, such as naming a PHP backdoor code with a file name of test.gif. A user may not know that a file is malicious due to the benign appearance and file extension.

Polyglot files, which are files that have multiple different file types and that function differently based on the application that will execute them, may also be used to disguise malicious malware and capabilities.

Kill Chain Phase

• Defense Evasion (TA0005)

Platforms: Linux, macOS, Windows

What to Check

• Identify if Masquerade File Type technique is applicable to target environment
• Check Linux systems for indicators of Masquerade File Type
• Check macOS systems for indicators of Masquerade File Type
• Check Windows systems for indicators of Masquerade File Type
• Verify mitigations are bypassed or absent (3 known mitigations)
• Assess detection coverage (1 detection strategies)

How to Test