Note: This is a multi-part series primer on the intersection of advanced persistent threats (APTs) and software supply chain security (SSCS). This blog post is the first in the series. We will update this blog post with links to the additional parts of the series as they are published.
• Part 1 (This blog post)
Part 2
Part 3

In the realm of cybersecurity, the convergence of Advanced Persistent Threats (APTs) and software supply chain security presents a uniquely daunting challenge for organizations. APTs, characterized by their sophisticated, state-sponsored or well-funded nature, focus on stealthy, long-term data theft, espionage, or sabotage, targeting specific entities. Their effectiveness is amplified by the asymmetric power dynamics of a well funded attacker versus a resource constrained security team.

Modern supply chains inadvertently magnify the impact of APTs due to the complex and interconnected dependency network of software and hardware components. The exploitation of this weakness by APTs not only compromises the targeted organizations but also poses a systemic risk to all users of the compromised downstream components. The infamous Solarwinds exploit exemplifies the far-reaching consequences of such breaches.

This landscape underscores the necessity for an integrated approach to cybersecurity, emphasizing depth, breadth, and feedback to create a holistic software supply chain security program that can withstand even adversaries as motivated and well-resourced as APTs. Before we jump into how to create a secure software supply chain that can resist APTs, let's understand our adversary a bit better first.

Know Your Adversary: Advanced Persistent Threats (APTs)

What is an Advanced Persistent Threats (APT)?

An Advanced Persistent Threat (APT) is a sophisticated, prolonged cyberattack, usually state-sponsored or executed by well-funded criminal groups, targeting specific organizations or nations. Characterized by advanced techniques, APTs exploit zero-day vulnerabilities and custom malware, focusing on stealth and long-term data theft, espionage, or sabotage. Unlike broad, indiscriminate cyber threats, APTs are highly targeted, involving extensive research into the victim's vulnerabilities and tailored attack strategies.

APTs are marked by their persistence, maintaining a foothold in a target's network for extended periods, often months or years, to continually gather information. They are designed to evade detection, blending in with regular network traffic, and using methods like encryption and log deletion. Defending against APTs requires robust, advanced security measures, continuous monitoring, and a proactive cybersecurity approach, often necessitating collaboration with cybersecurity experts and authorities.

High-Profile APT Example: Operation Triangulation

The recent Operation Triangulation campaign disclosed by Kaspersky researchers is an extraordinary example of an APT in both its sophistication and depth. The campaign made use of four separate zero-day vulnerabilities, utilized a highly targeted approach towards specific individuals at Kaspersky, combined a multi-phase attack pattern and persisted over a four year period. Its complexity, implied significant resources possibly from a nation-state, and the stealthy, methodical progression of the attack, align closely with the hallmarks of APTs. Famed security researcher, Bruce Schneier, writing on his blog, Schneier on Security, wasn't able to contain his surprise upon reading the details of the campaign, "[t]his is nation-state stuff, absolutely crazy in its sophistication."

What is the impact of APTs on organizations?

Ignoring the threat posed by Advanced Persistent Threats (APTs) can lead to significant impact for organizations, including extensive data breaches and severe financial losses. These sophisticated attacks can disrupt operations, damage reputations, and, in cases involving government targets, even compromise national security. APTs enable long-term espionage and strategic disadvantage due to their persistent nature. Thus, overlooking APTs leaves organizations exposed to continuous, sophisticated cyber espionage and the multifaceted damages that follow.

Now that we have a good grasp on the threat of APTs, we turn our attention to the world of software supply chain security to understand the unique features of this landscape.

Setting the Stage: Software Supply Chain Security

What is Software Supply Chain Security?

Software supply chain security is focused on protecting the integrity of software through its development and distribution. Specifically it aims to prevent the introduction of malicious code into software that is utilized as components to build widely-used software services.

The open source software ecosystem is a complex supply chain that solves the problem of redundancy of effort. By creating a single open source version of a web server and distributing it, new companies that want to operate a business on the internet can re-use the generic open source web server instead of having to build its own before it can do business. These new companies can instead focus their efforts on building new bespoke software on top of a web server that does new, useful functions for users that were previously unserved. This is typically referred to as compostable software building blocks and it is one of the most important outcomes of the open source software movement.

But as they say, "there are no free lunches". While open source software has created this incredible productivity boon comes responsibility. 

What is the Key Vulnerability of the Modern Software Supply Chain Ecosystem?

The key vulnerability in the modern software supply chain is the structure of how software components are re-used, each with its own set of dependencies, creating a complex web of interlinked parts. This intricate dependency network can lead to significant security risks if even a single component is compromised, as vulnerabilities can cascade throughout the entire network. This interconnected structure makes it challenging to ensure comprehensive security, as a flaw in any part of the supply chain can affect the entire system.

Modern software is particularly vulnerable to software supply chain attacks because 70-90% of modern applications are open source software components with the remaining 10-30% being the proprietary code that implements company specific features. This means that by breaching popular open source software frameworks and libraries an attacker can amplify the blast radius of their attack to effectively reach significant portions of internet based services with a single attack.

If you're looking for a deeper understanding of software supply chain security we have written a comprehensive guide to walk you through the topic in full.

High-Profile Software Supply Chain Exploit Example: SolarWinds

In one of the most sophisticated supply chain attacks, malicious actors compromised the update mechanism of SolarWinds' Orion software. This breach allowed the attackers to distribute malware to approximately 18,000 customers. The attack had far-reaching consequences, affecting numerous government agencies, private companies, and critical infrastructure.

Looking at the example of SolarWinds, the lesson we should take away is not to put a focus on prevention. APTs has a wealth of resources to draw upon. Instead the focus should be on monitoring the software we consume, build, and ship for unexpected changes. Modern software supply chains come with a great deal of responsibility. The software we use and ship need to be understood and monitored.

This is the first in a series of blog posts focused on the intersection of APTs and software supply chain security. This blog post highlighted the contextual background to set the stage for the unique consequences of these two larger forces. Next week, we will discuss the implications of the collision of these two spheres in the second blog post in this series.