Many organisations pride themselves on their cybersecurity defences. They have firewalls, endpoint protection, multi-factor authentication, the works. But here’s the uncomfortable truth: it might not be your network that hackers are after. It might be your suppliers, your software providers, or even the logistics firm handling your deliveries.

Cybercriminals changed tactics. Instead of banging on the front door, they’re creeping in through the back, exploiting weaker links in the supply chain. And with today’s interconnected business world, there are plenty of backdoors to choose from.

The New Attack Surface

Think about how many third parties your organisation relies on. SaaS platforms, cloud hosting providers, outsourced IT services, payroll systems, suppliers, consultants, the list is endless. Each of these relationships represents a potential entry point for attackers.

The problem is, most businesses assume their security is enough. But if your trusted partner has a vulnerability, it might as well be your own.

Take the infamous SolarWinds attack as an example. Hackers didn’t breach individual companies directly; they compromised the software provider, pushing malicious updates to thousands of unsuspecting customers. The result? A supply chain breach that impacted governments and Fortune 500 companies alike.

OSINT: Mapping the Weak Links

Hackers don’t randomly stumble upon these weak points, they actively look for them using OSINT (Open-Source Intelligence). OSINT is the art of gathering publicly available information to build a picture of an organisation’s structure, technology stack, and external partnerships.

With the right data, attackers can uncover:

• Which third-party vendors a company relies on
• What software they use (and whether it has known vulnerabilities)
• Who the key employees are (and whether they’re easy targets for phishing)

From social media to job postings, from leaked credentials to forgotten subdomains—OSINT is a goldmine for cybercriminals. They don’t need to break into your business if they can walk in through an unlocked side door.

Are You Vetting Your Vendors?

Most organisations conduct rigorous penetration testing and security audits for themselves, but how many extend that scrutiny to their suppliers? It’s uncomfortable to admit, but many vendors simply don’t meet the same security standards.

If your supplier gets hacked, you get hacked. If their credentials are exposed, yours could be too. And if they’re the weak link, you won’t even see the breach coming.

The solution isn’t just stronger internal security, it’s third-party risk management. Companies need to start treating their supply chain as an extension of their own security perimeter. That means:

• Due diligence before signing contracts
• Regular security assessments for vendors
• Continuous monitoring for supplier risks
• Tighter access controls on third-party integrations
• Incident response plans that account for supply chain breaches

Cybercriminals know that organisations focus on their own defences while often neglecting their partners. That’s exactly why these attacks are so successful.

The Bottom Line

The next big cyberattack won’t necessarily come from a direct assault on your systems. It might come from a trusted partner, a software update, or a contractor with weak security. Cybercriminals don’t just attack businesses anymore, they attack ecosystems.

If you’re serious about cybersecurity, it’s time to stop thinking in silos. Your business isn’t an island; it’s part of a network. And in cybersecurity, a chain is only as strong as its weakest link.

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