Standard attack pattern

Draft

CAPEC-523: Malicious Software Implanted

An attacker implants malicious software into the system in the supply chain distribution channel, with purpose of causing malicious disruption or allowing for additional compromise when the system is deployed.

Last updated June 1, 2026

High

Typical severity

Per MITRE

Low

Likelihood of attack

Per MITRE

0

Related weaknesses

CWEs this targets

Standard

Abstraction

MITRE classification

Overview

CAPEC-523 (Malicious Software Implanted) is a standard-level attack pattern catalogued by MITRE in the Common Attack Pattern Enumeration and Classification (CAPEC). It describes a recurring method attackers use to exploit software weaknesses.

How the attack works

The phases an attacker typically follows to carry out this attack.

Step 1
Explore
[Determine Entry Point] The adversary must first identify a system that they wish to target and search for an entry point they can use to install the malicious software. This could be a system which they have prior knowledge of, giving them insight into the software and environment.
- Use a JTAGulator to identify exposed JTAG and UART interfaces in smaller embedded systems.
- Identify exposed USB connectors that could be used to load software.
Step 2
Explore
[Discover Vulnerability in Supply Chain] The adversary maps out the supply chain for the targeted system. They look for ooportunities to gain physical access to the system after it has left the manufacturer, but before it is deployed to the victim.
- Procure a system and observe the steps it takes in the shipment process.
- Identify possible warehouses that systems are stored after manufacturing.
Step 3

Experiment

[Test Malicious Software] Before performing the attack in the wild, an adversary will test the attack on a system they have procured to ensure that the desired outcome will be achieved.

Design malicious software that will give an adversary a backdoor into the system once it is deployed to the victim.
Obtain already designed malicious software that just need to be placed into the system.

Step 4

Exploit

[Implant Software in the Supply Chain] Using the vulnerability in the supply chain of the system discovered in the explore phase, the adversary implants the malicious software into the system. This results in the adversary gaining unintended access to systems once they reach the victim and can lead to a variety of follow up attacks.

What the attacker needs

Prerequisites

Physical access to the system after it has left the manufacturer but before it is deployed at the victim location.

Skills required

High skill: Advanced knowledge of the design of the system and it's operating system components and subcomponents.
High skill: Malicious software creation.

How to mitigate it

Defenses that reduce the risk of CAPEC-523.

Deploy strong code integrity policies to allow only authorized apps to run.
Use endpoint detection and response solutions that can automaticalkly detect and remediate suspicious activities.
Maintain a highly secure build and update infrastructure by immediately applying security patches for OS and software, implementing mandatory integrity controls to ensure only trusted tools run, and requiring multi-factor authentication for admins.
Require SSL for update channels and implement certificate transparency based verification.
Sign everything, including configuration files, XML files and packages.
Develop an incident response process, disclose supply chain incidents and notify customers with accurate and timely information.

Examples

An attacker has created a piece of malicious software designed to function as a backdoor in a system that is to be deployed at the victim location. During shipment of the system, the attacker has physical access to the system at a loading dock of an integrator for a short time. The attacker unpacks and powers up the system and installs the malicious piece of software, and configures it to run upon system boot. The system is repackaged and returned to its place on the loading dock, and is shipped and installed at the victim location with the malicious software in place, allowing the attacker to bypass firewalls and remotely gain access to the victim's network for further malicious activities.

Terminology & mappings

Mapped taxonomies

ATTACK: Supply Chain Compromise: Compromise Software Supply Chain (1195.002)

Frequently asked questions

Common questions about CAPEC-523.

What is CAPEC-523?

An attacker implants malicious software into the system in the supply chain distribution channel, with purpose of causing malicious disruption or allowing for additional compromise when the system is deployed.

How does a Malicious Software Implanted attack work?

It typically unfolds over 4 phases. It begins with: [Determine Entry Point] The adversary must first identify a system that they wish to target and search for an entry point they can use to install the malicious software. This could be a system which they have prior knowledge of, giving them insight into the software and environment.

How do you prevent CAPEC-523?

Deploy strong code integrity policies to allow only authorized apps to run.

How severe is CAPEC-523?

MITRE rates CAPEC-523 as High severity with low likelihood of attack.

References

Attack-pattern data is sourced from the MITRE CAPEC catalog (v3.9). Weakness associations link to the corresponding CWE entries on RadicalNotion.AI.

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