Supply Chain Attacks: What They Are and How You Can Protect Yourself

Imagine performing a software update you fully trust—after all, it’s from a reputable vendor. Instead of delivering security patches, however, the update brings in a digital backdoor that opens your systems to cybercriminals. What sounds like a Hollywood thriller scenario has become a stark reality:
This is precisely what happened during the notorious SolarWinds attack in 2020, which compromised thousands of organizations and even government agencies, and more recently with 3CX in 2023, when a manipulated app endangered hundreds of thousands of users.

These so-called supply chain attacks do not directly target large corporations or government entities; instead, they go after smaller, often less protected links in the supply chain. A single compromised service provider or infected software module can trigger a chain reaction that, in the worst-case scenario, can paralyze entire industries. Dramatic examples like Stuxnet (which targeted Iranian nuclear facilities) or the hacker attack on the major US retailer Target vividly demonstrate that no one is immune: Even highly secured networks can be breached if a supplier or external component is manipulated.

But how exactly do these attacks work, hiding behind seemingly harmless updates? Why are they so hard to detect—and even harder to fight? And above all, what steps can you take as a company or a tech-savvy private user to protect yourself against this highly dangerous attack vector? In this article, we’ll provide an overview of how these attacks work, showcase some of the most notorious examples, and highlight the most effective countermeasures. We’ll also explain how Protectstar’s Supply Chain Risk Management (SCRM) works in detail and how our rigorous processes prevent malicious software from being inserted unnoticed during development.

1. What Is a Supply Chain Attack?

A supply chain attack is a form of cyberattack in which criminals do not directly attack the primary target but instead use an indirect route via third-party providers, suppliers, or external software components. This indirect approach has a straightforward reason: Large organizations and corporations typically have advanced security measures, so a “frontal attack” is resource-intensive and risky. In contrast, smaller suppliers or external service providers often have fewer complex security mechanisms, making them a comparatively easy entry point.

How Does It Work?

A classic scenario goes like this: Hackers compromise the software of a trusted vendor by injecting malicious code into an otherwise legitimate update. Customers install the update believing it to be harmless. Once installed, the attackers gain unnoticed access to the victims’ systems. Potentially, tens of thousands of devices or networks can be infected simultaneously. One particularly high-profile example is the SolarWinds hack in 2020.

Why This Approach?

Path of Least Resistance: Attempting to break directly into the highly secured networks of major corporations or government agencies often involves multiple firewalls, intrusion prevention systems, and security teams. It’s much easier to target a smaller supplier or IT service provider who regularly has access to the target systems but operates with far less stringent security protocols. Statistics back this up: According to a Verizon study, 92% of successful cyberattacks happen at smaller companies, which then serve as springboards to the real target.

2. Notable Examples of Supply Chain Attacks

Below are some of the most significant supply chain attacks. These examples illustrate that virtually any industry or technology can be affected—from ordinary corporate networks to specialized industrial control systems and popular consumer applications.

SolarWinds (2020)

The SolarWinds hack is considered one of the most severe supply chain attacks in recent years:

• Background: SolarWinds is a U.S.-based IT service provider known for, among other things, its popular Orion network management software. Agencies, large corporations, and managed service providers (MSPs) around the world rely on SolarWinds products to monitor their IT infrastructures.
• Attack Procedure: The attackers—presumably a Russian hacker group referred to by many security experts as “Cozy Bear” (APT29)—infiltrated the SolarWinds build environment. There, they injected the malicious “SUNBURST” code directly into Orion updates. Since these updates were officially signed, customers saw no difference from regular version updates.
• Timeline: The compromise likely began in spring 2020. The infected updates were distributed from March 2020 onward and were only discovered in December 2020, when cybersecurity firm FireEye became suspicious.
• Exploitation: The “SUNBURST” backdoor enabled hackers to steal data and deploy additional malware. Because the malware was officially signed, it went undetected for months.
• Scope: Around 18,000 customers—including several U.S. government agencies (e.g., the Department of the Treasury and the Department of Commerce) and multinational corporations—were potentially affected. In reality, the attackers probably only made use of a fraction of those entry points, making the full extent difficult to ascertain.

Consequences:

• Political Fallout: The U.S. government responded with new guidelines for software development and increased collaboration with private security companies.
• Loss of Trust: SolarWinds suffered massive reputational damage and faced legal repercussions. Many companies also reconsidered their update and supply chain processes.

This incident vividly demonstrated how devastating the abuse of an update infrastructure can be. A single compromised vendor triggered a global security crisis in a very short time.

3CX (2023)

In March 2023, 3CX, a provider of VoIP and UC solutions, became the victim of a large-scale supply chain attack:

• Background: 3CX software is used across numerous industries, offering flexible communication solutions. Its desktop apps for Windows and macOS are especially widespread.
• Compromising the Desktop App: The attackers managed to manipulate the 3CX installation process. During setup, a Trojan was secretly loaded, creating a channel for data exchange with an external command-and-control (C2) server.
• Possible Precursor: Analyses by several security teams (including CrowdStrike) suggest a “double supply chain attack.” The attackers may have already compromised other software before using it to infiltrate 3CX.
• Suspected Perpetrators: Industry experts link the attack to the North Korean hacker group Lazarus, notorious for espionage and financial attacks, often using Trojans to exfiltrate confidential data.
• Affected Users: Because 3CX is used internationally by numerous companies and public agencies, the potential for damage was enormous. Estimates range from hundreds of thousands to potentially millions of affected systems.

Impact:

Data Theft: The attackers primarily aimed to steal sensitive information, login credentials, and communication logs.

Reputational Damage: 3CX had to respond rapidly to restore trust. Patches and security advisories were released in short order. However, many customers were shaken because they had relied on an officially verified installation routine.

The 3CX incident shows how sophisticated hacker groups have become in going after software supply chains and how even widely used communications services can become an entry point.

Stuxnet (2010)

Although somewhat older, the Stuxnet worm remains a striking example of a highly advanced supply chain attack—and is often described as the first true cyberweapon:

Objective: Stuxnet targeted Siemens control systems (SCADA) used in Iran’s nuclear program, particularly attacking uranium enrichment centrifuges.

Attack Method:

• Infection via USB Sticks: Because the network was isolated (air-gapped), it couldn’t be directly attacked via the internet. A compromised USB stick made its way into the internal network, likely brought in by external technicians or unwitting employees.
• Zero-Day Exploits: Stuxnet took advantage of multiple unknown (zero-day) vulnerabilities in Windows, allowing it to spread undetected and specifically manipulate the Siemens Step7 software.

Functionality:

• Sabotage: Stuxnet tampered with the centrifuge controller by secretly changing their rotational speed. At the same time, it ensured that the monitoring software displayed normal values. As a result, the centrifuges were damaged without immediate detection.
• Background: Researchers believe this may have been a joint effort by the U.S. and Israel to hinder Iran’s nuclear program.

Significance:

• Milestone in IT Security: Stuxnet was the first publicly documented case of a cyberattack aimed at physically sabotaging industrial equipment.
• Learning Curve: These events led to a surge in security measures for industrial control systems (ICS), as it became evident that even specialized, supposedly isolated installations can be vulnerable.

Even though Stuxnet wasn’t introduced through conventional software updates, it stands as a prime example of how an attack can begin “within the chain”—in this instance, via physical transmission with infected media.

Additional Cases (Target, NotPetya, CCleaner, etc.)

Supply chain attacks can hit nearly any sector. Three notable examples show the broad scope of the problem:

• Target (2013): The major U.S. retailer Target suffered a huge data breach when criminals stole login credentials from a third-party HVAC (heating, ventilation, air conditioning) supplier. Using this privileged access, they obtained 40 million credit card records. Customer confidence was severely undermined, and Target incurred high costs for reimbursements and security upgrades.
• NotPetya (2017): This malware masqueraded as ransomware but was in fact a destructive wiper that permanently erased data. Spread through an update of the Ukrainian accounting software MeDoc, it caused billions in damages worldwide. Companies like Maersk and Merck were severely affected, some having to rebuild their IT infrastructures from scratch.
• CCleaner (2017): Attackers compromised the development environment of Piriform (later acquired by Avast), injecting malware into the popular PC utility CCleaner’s official installer. Millions of computers were impacted globally. The attackers focused in particular on infiltrating large tech companies, where a second-stage malware (selective espionage) was activated.

These examples show that no one should be lulled into a false sense of security. Retailers, industrial facilities, or software developers—any part of a supply chain can become the launchpad for an attack.

3. Why Are Supply Chain Attacks So Dangerous?

Supply chain attacks pose a massive threat and often have far-reaching consequences. Here are the main reasons:

• Massive Damage: A single breach can affect thousands of customers and millions of end users—especially if widely used software is infected.
• Exploitation of Trust: Conventional security measures are bypassed because the malicious component (e.g., a signed update) appears to be legitimate.
• Difficulty of Detection: Because the infection arrives through officially certified channels, backdoors often remain hidden for months.
• Long-Term Consequences: Once hardware or firmware is compromised, it can be extremely difficult to remediate. In some cases, it may even survive operating system reinstalls.
• Broad Attack Surface: Ongoing globalization and extensive interconnectivity constantly expand the complexity and number of links in any given supply chain.

4. How Can You Protect Yourself?

Neither companies nor private users can afford to ignore the risks in their supply chains. However, there are several well-established measures that can significantly reduce the threat:

1. Careful Selection and Verification of Suppliers: Security audits, certifications, and mandatory standards should be part of supplier agreements.
2. Principle of Least Privilege: Third parties only get the minimum level of access that is strictly necessary, and this access is closely monitored.
3. Secure the Software Supply Chain: Verify integrity and authenticity of updates, use only official sources, and conduct code reviews.
4. Software Bill of Materials (SBOM): Document all libraries and components in use so you can swiftly address any emerging vulnerabilities.
5. Active Monitoring and Quick Patching: Implement monitoring to detect suspicious activity early, and consistently apply security patches, including firmware updates.
6. Emergency Plan and Incident Response: An incident response plan minimizes damage if an attack does succeed. Cyber insurance can mitigate financial risks.

5. Protectstar’s Approach: Supply Chain Risk Management (SCRM)

Protectstar is fully aware of the escalating threat posed by supply chain attacks. For this reason, we’ve implemented our own Supply Chain Risk Management (SCRM) that covers every stage of development and product integration. Learn more in our blog article at
https://www.protectstar.com/en/blog/supply-chain-risk-management-scrm-why-its-indispensable-for-your-security

Our approach is built around several core principles:

• Thorough Review of Every Component: No external library or module is integrated into our products without rigorous security checks (code reviews, audits, penetration tests). An SBOM ensures we can respond immediately to newly discovered vulnerabilities.
• Compliance with Recognized Security Standards: We strictly follow NIST guidelines (e.g., SP 800-161 for supply chain risk management) and ISO/IEC 27036 for secure supplier relationships. We also adhere to OWASP recommendations for secure software development.
• Regular Audits and Certifications: Several of our apps have received DEKRA MASA L1 certification, and renowned institutions like AV-TEST have awarded our security apps multiple times. Every code change is transparently documented and evaluated.
• Continuous Improvement: We employ self-learning AI models (Antivirus AI, Firewall AI) to identify zero-day attacks at the outset. Achieving detection rates of over 99.8% and virtually no false alarms, these solutions deliver multi-layered protection, complemented by tools such as Anti Spy and the data erasure app iShredder.

By combining these elements, we create a seamless security chain—from the first line of code to the end-user download. Any potential vulnerability is identified and eliminated before it ever reaches our users.

6. Conclusion

Supply chain attacks have grown into a substantial threat in recent years. From manipulated software updates to compromised hardware components and even USB sticks that introduce malware into supposedly secure environments: Attackers exploit the high level of trust inherent in supplier relationships. The repercussions can be devastating, impacting not just single organizations but entire sectors and government agencies.

Yet no one is powerless against these attacks. A robust Supply Chain Risk Management strategy can greatly reduce the likelihood of a breach. Key elements include carefully vetting suppliers, managing privileges effectively, promptly detecting and patching vulnerabilities, and developing a clear incident response plan for emergencies.

At Protectstar, we demonstrate what a fully integrated security strategy looks like: Through stringent testing procedures, continuous audits, adherence to international standards, and the deployment of cutting-edge AI technologies, we ensure that attackers never get a foothold in the first place. In an era where digital threats are increasingly sophisticated and elusive, this level of diligence is indispensable.

Anyone following these guidelines establishes a solid defensive ring—protecting their systems, data, and business processes from one of the most dangerous attack vectors today. This way, trustworthy updates remain genuinely trustworthy, and should a weak link appear somewhere in the digital supply chain, damage can be contained swiftly or even prevented entirely. Ultimately, it’s this proactive, holistic perspective that makes all the difference between security and vulnerability in an interconnected world.