What Is a Supply Chain Cyberattack?

A supply chain cyberattack occurs when an attacker compromises a vendor, supplier, or partner that has access to their intended target — and uses that trusted relationship to reach the real objective. The attack can target software (malicious code inserted into a legitimate software update or open-source package), managed services (compromising an MSP to reach all of their clients simultaneously), or hardware (tampering with components before they reach the end user). What makes supply chain attacks particularly dangerous is the exploitation of trust: your security controls are designed to block untrusted access, but when the attack arrives via a vendor you’ve explicitly authorized, the normal defensive mechanisms don’t trigger. The MOVEit file transfer vulnerability in 2023 exposed thousands of organizations through a single software product, demonstrating that a single supply chain compromise can cascade to affect an enormous number of downstream targets simultaneously. Defense contractors, healthcare providers, financial institutions, and government agencies were all impacted.

Why Supply Chain Attacks Are Increasing

Supply chain attacks are increasing for several interconnected reasons. First, direct attack paths have become harder and more expensive as organizations improve their perimeter defenses — attackers have adapted by finding softer entry points in the supply chain. Second, software supply chains have become extraordinarily complex: the average enterprise application depends on hundreds of open-source libraries, each of which represents a potential injection point for malicious code. Third, the payoff from supply chain attacks is disproportionately high — compromising a single widely-used software vendor or managed service provider gives attackers access to hundreds or thousands of downstream targets in a single operation. Nation-state actors in particular favor supply chain attacks because they enable mass collection and positioning with a single operation. The U.S. government’s response — including Executive Orders on software supply chain security and CISA’s supply chain risk management guidance — reflects how seriously this threat has been elevated in the national security context.

Software Supply Chain Risk — What You Need to Know

Software supply chain risk encompasses the open-source libraries in your applications, the third-party SaaS tools your organization uses, the software update mechanisms that could deliver malicious code, and the development pipeline components (CI/CD tools, code repositories) that, if compromised, could inject malicious code into your own software before it ships. A Software Bill of Materials (SBOM) — a formal inventory of all software components in an application — has become a key tool for understanding and managing this risk. The U.S. government now requires SBOMs from software vendors selling to federal agencies under Executive Order 14028. For most small businesses, the practical implication is simpler: know what software you’re using, ensure you’re getting it from authoritative sources, keep it updated, and have a process for responding quickly when a critical vulnerability is disclosed in software you depend on.

Hardware Supply Chain Security

Hardware supply chain risk is less commonly discussed but increasingly relevant, particularly for defense contractors and organizations with high-security requirements. Hardware tampering — inserting malicious components into network equipment, servers, or end-user devices during manufacturing or shipping — can create persistent backdoors that survive software reimaging. Counterfeit networking equipment sold through secondary markets has been documented in multiple federal investigations. Practical controls for hardware supply chain security include purchasing from authorized resellers and manufacturers rather than gray market sources, inspecting hardware physically before deployment for signs of tampering, using BIOS/UEFI integrity measurements to detect firmware modifications, and maintaining an asset inventory with hardware provenance documentation. For organizations subject to DFARS or CMMC requirements, supply chain risk management (SCRM) is an explicit control requirement under NIST SP 800-161.

How to Build Supply Chain Security Requirements for Your Vendors

• Require software transparency: For critical software vendors, request SBOMs and vulnerability disclosure policies. Know what’s inside the tools you depend on.
• Contractual security requirements: Include software security requirements in vendor contracts — secure development practices, vulnerability notification timelines, and patch SLAs for critical issues.
• Monitor for compromise indicators: Subscribe to threat intelligence feeds and CISA advisories that flag active exploitation of software you use.
• Limit blast radius: Apply least privilege to all vendor and software access. A compromised tool that has minimal permissions causes minimal damage.
• Incident response for third-party incidents: Have a documented process for evaluating your exposure and responding quickly when a vendor you use announces a breach or critical vulnerability.
• Verify update integrity: Use code signing verification and official update channels to ensure software updates come from legitimate sources.