Sometimes the most dangerous piece of software is the one you didn’t even write. With supply chain attacks on the rise, software supply chain security is now critical to protecting not just your code, but everything your code depends on.
When we talk about a “supply chain,” most people picture the journey of a physical product: from raw materials through manufacturing to assembling, distribution, and sale. Obviously, no company does it all alone; they rely on a network of partners to make it happen.
Software works the same way.
Modern applications aren’t built from scratch, they’re assembled. Behind every app is a complex ecosystem of developer tools, CI/CD systems, cloud services, and open-source code. As The Linux Foundation reports, 70 to 90% of most applications today are made up of third-party components.
That means every time you run or build software, you’re depending on hundreds of interconnected moving parts. And if just one of those links is compromised, the whole system is at risk.
We saw that risk explode into reality recently.
Cycode states that a phishing campaign led to the hijacking of core NPM packages like chalk, debug, and strip-ansi, libraries downloaded over 2 billion times per week. SC Media reports that days later, another attack infected more than 200 NPM packages, including those linked to CrowdStrike, using a self-replicating worm that exfiltrated data, created rogue GitHub workflows, and attempted to spread downstream.
These weren’t targeted attacks. They were ecosystem-level compromises with the potential to impact millions, which is why Software Supply Chain Security matters now more than ever.
NEVEN MATAS, CYBERSECURITY TEAM DIRECTOR, INFINUM
It’s no longer just about writing secure code, it’s about securing everything you rely on to build, deploy, and maintain it.
In this article, we’ll introduce supply chain security and cover best practices for reducing risk – from defining requirements all the way to development, deployment, and maintenance.
The topics we’ll cover include:
So, what is Software Supply Chain Security (SSCS)?
Software Supply Chain Security (SSCS) is the practice of securing all the components, tools, people, and processes involved in the development, deployment, and maintenance of software, from third-party libraries and CI/CD pipelines to developer environments and cloud infrastructure.
If you’re only securing your app but ignoring the tools and dependencies you use to build it, you’re not secure. Modern software isn’t built from scratch. It’s assembled. And even a single vulnerable dependency can compromise your entire product.
That’s why SSCS is a critical part of secure software development. It ensures every link in the chain is trusted, verified, and resilient. It’s also why regulations like NIS2 put so much emphasis on it.
What are the most common threats in the software supply chain?
Software supply chain security goes far beyond writing secure code. It’s about making sure malicious actors can’t sneak in through the tools, environments, and people your app depends on.
Here are some of the most common entry points attackers exploit:
- Open-source dependencies that could contain malicious code
- Package managers and artifact repositories that could distribute malicious packages
- Source code repositories (GitHub, GitLab…) that may be targeted for unauthorized access
- Build tools and environments that can be tampered with to insert malicious artifacts
- CI/CD systems that are attractive targets for attackers to introduce compromised code into production
- Cloud infrastructure and third-party services that could be exploited to gain access
- Developer machines and IDEs that, if infected, could be a direct path towards compromising code
- Your own team, because human error is always the biggest risk
Most common types of supply chain attacks
Once inside, here’s what those attacks can look like in the real world:
- Vulnerable components – outdated or unpatched dependencies (remember Log4j?)
- Malicious packages – rogue npm/PyPI uploads hiding backdoors or malware
- Build pipeline tampering – injecting malicious code during build (e.g. SolarWinds)
- Fake maintainers – attackers hijacking open-source projects to slip in malicious commits
- Secrets leakage – exposed API tokens or credentials in public repos
- Weak repo security – no MFA, poor audit trails, accounts vulnerable to takeover
- Overprivileged scripts – CI/CD or deploy scripts with excessive permissions
- Dependency confusion – lookalike packages from public registries winning the name race
- Compromised dev environments – malware on a single laptop can be all it takes
- Hijacked CI/CD runners – shared runners or agents used to execute malicious code
- Poisoned artifacts or registries – malicious Docker images or tampered packages
- Pre-installed backdoors – third-party SDKs or libraries phoning home
- Social engineering – phishing maintainers or tricking devs into handing over keys
And that’s not even an exhaustive list.
Many of these attacks exploit gaps in the development process itself.
Even if your code is secure and your infrastructure hardened, vulnerabilities can slip in when there’s limited visibility, inconsistent practices, or missing security checks — which is why integrating security throughout the Software Development Lifecycle (SDLC), often referred to as the Secure Software Development Lifecycle (SSDLC), is so valuable.
Integrating security at every stage of the SDLC
The SSDLC encourages embedding security practices at every stage of development. This approach, often referred to as “shifting left”, helps identify and remediate threats early, before they reach production.
It doesn’t eliminate supply chain risks entirely, but it reduces the risk of vulnerabilities slipping through unnoticed and the likelihood that compromised dependencies, misconfigured pipelines, or weak controls turn into full-blown breaches.
‘Shift left’ means integrating security earlier in the development process, so threats are identified and fixed long before they reach production.
Here’s what that can look like:
- Defining security requirements during planning
- Performing threat modeling during design
- Using automated tools to scan for vulnerabilities during development and testing
- Securing your CI/CD workflows and access controls during build and deployment
- Maintaining clear incident response plans during operations
How to adopt secure software development lifecycle (SSDLC) practices
Let’s break it down through some high-level SSDLC phases and their security-minded steps:
1. Planning
Planning is arguably the most critical step for supply chain security, as it helps prevent hidden vulnerabilities through thorough due diligence.
- Perform a risk analysis to identify assets, assess threats, and decide how to handle each risk (avoid, transfer, mitigate, or accept)
- Define security and compliance requirements based on the risk analysis
- Assess third-party risk through vendor reviews and security questionnaires
- Ensure SLAs and contracts include clear, enforceable security terms that work in your favor
- Identify relevant standards and compliance obligations (e.g., ISO 27001, SOC 2) for vendors and third-party software
2. Design
Design is your chance to build supply chain defenses into the architecture.
- Conduct threat modeling to identify potential attack vectors
- Select secure architecture patterns and apply least privilege, zero trust, and secure defaults principles from the start
- Define clear trust boundaries between internal components and third-party integrations
- Plan for secure communication channels, including encryption in transit and at rest
3. Development
Development is where insecure code or unvetted dependencies can silently enter your supply chain.
- Enforce secure coding standards (e.g., OWASP)
- Enforce pull requests (PRs) reviews to ensure code quality and security before merging
- Use properly configured SCA tools (Software Composition Analysis) in the CI pipeline to identify and manage security risks in third-party libraries and open-source dependencies
- Scan for secrets and credentials in code
- Restrict sensitive projects to private repositories and limiting access to authorized developer teams only
4. Testing
Testing is where you validate not just your code, but the behavior of any external components or APIs. It helps expose risks before they become real threats
- Use SAST (Static Application Security Testing) tools in the CI pipeline to detect vulnerabilities and insecure coding patterns before it reaches production
- Use DAST (Dynamic Application Security Testing) tools to identify security vulnerabilities in a running application by simulating real-world attacks
- Perform regular penetration tests to simulate real-world attacks and identify vulnerabilities an attacker could actually exploit – not just what a scanner detects.
5. Build & deploy
Build and deployment pipelines are a prime target for supply chain attacks. Securing CI/CD is a non-negotiable for trust and integrity.
- Enforce strong authentication and role-based access controls (RBAC) for build systems
- Centralize and automate secret management (e.g., HashiCorp Vault)
- Harden all environments—including staging and production—as well as the CI/CD infrastructure (e.g., by using isolation, comprehensive logging, and ephemeral runners)
- Sign build artifacts and verify their integrity before deployment to ensure that the software has not been tampered with
6. Distribution
Distribution is when your software becomes part of someone else’s supply chain. It helps build trust and transparency with clients and downstream users.
- Maintain and distribute SBOMs (Software Bill of Materials) to track all software components
- Scan packages pre- and post-publish for malware or vulnerabilities
7. Maintenance
Maintenance ensures your supply chain remains secure over time. Nothing is more dangerous than running software that becomes forgotten.
- Continuously monitor for new CVEs (Common Vulnerabilities and Exposures) and third-party advisories
- Regularly audit and harden configurations (cloud, infra, access policies)
- Automate patching and dependency updates
- Replace insecure or deprecated components
- Maintain and rehearse incident response plans for supply chain attacks (including backup and disaster recovery procedures) to ensure supply chain resilience
- Periodically reassess vendor and third-party risks to capture changes in their security posture
Security isn’t a checkbox at the end of your sprint, it’s a continuous mindset that spans every phase of development. Adopting SSDLC practices means baking security into your process, not bolting it on after the fact.
You don’t need to get it perfect from day one. Just start building with intention, iterate often, and treat security as a shared responsibility across your stack.
Which industry standards and frameworks to explore for SSDLC?
Luckily for you, you don’t have to start from scratch.
There are frameworks built by security pros to help you get it right. Use OWASP SAMM, NIST SSDF, or Microsoft’s SDL as a baseline to evaluate your current practices and make steady, structured improvements.
How to build a response plan and keep your security policies sharp
The worst time to figure out your incident response plan is while the incident is happening.
Investing time into developing a clear, actionable incident response plan is non-negotiable.
You need to know how you’ll detect an incident, who’s responsible for what, how to contain it, and how to communicate both internally and externally. The worst time to figure it out is while it’s happening.
And that’s just the beginning.
As software evolves, so do the threats. If your security policies are stuck in last year’s playbook, you’re not protected. Review and update your practices regularly, from dependency management and access control to patching and third-party risk.
Stay informed, stay adaptable, and stay ahead before someone else forces you to.
How to manage human risk in the supply chain security
Technology alone isn’t enough. Security depends on people, and people are often the easiest way in.
Phishing and social engineering remain some of the most effective tactics in supply chain attacks. Recent incidents like the hijacking of chalk and debug began with a fake MFA email sent to a trusted maintainer. No zero-days. No malware. Just a well-crafted message and a moment of inattention.
That’s why security culture matters as much as security tooling.
Start with the basics:
- Code reviews with security checklists – don’t rely on automation alone
- Pair programming – share knowledge, spot issues early
- Regular security training – not just once a year, but as an ongoing habit
- Simulated phishing campaigns – train your team to recognize real threats
- Fostering a security-first culture – where reporting issues is expected, not punished
- Cross-functional collaboration – involve product, legal, and ops in risk decisions
Isn’t this all a bit too much?
Yes, it can feel like a lot. But you don’t need to boil the ocean, just start where it matters most. Use a model like OWASP SAMM to assess where you stand, identify your biggest risks, and go for a few quick wins.
Here are a few that pack a punch:
- Set up an SCA tool in under an hour (e.g, Dependabot).
- Add 2FA on your GitHub org today – no excuses
- Add a “security” section to your pull request template.
- Run a penentration test
- Draft a basic incident response doc for your team.
Security maturity comes from small, consistent moves in the right direction
Remember: you can outsource code, but you can’t outsource accountability. What matters most is building a culture where no one makes security the other person’s job.
Proceed to shift security left, raise awareness, automate what you can, patch early, and document everything. If you need some extra support, feel free to reach out to our certified experts.
