When was the last time you asked yourself, “What would we actually do if we lost access to all our business data overnight?”

That’s not just a hypothetical anymore. The FBI has issued a fresh warning about a fast-moving ransomware group called Interlock, and they’re not playing games.

Who is Interlock and why should you care?

Interlock only surfaced in late 2024, but they’ve already made a name for themselves by targeting businesses and infrastructure across North America and Europe. Their approach? Classic double-extortion. First, they sneak into your systems and quietly steal sensitive data. Then they lock you out of your own files and demand a ransom. If you don’t pay up (usually within four days) they threaten to leak everything on the dark web.

It’s brutal. And it’s working.

How do they get in?

Interlock’s tactics are clever and designed to catch people off guard. They use fake browser updates, malicious websites, and other tricks to lure users into clicking. Once inside, they deploy a suite of tools to spy, steal passwords, move laterally across your network, and encrypt everything they touch.

They’re not fussy about what systems you use either. Whether you’re running Windows or Linux, you’re fair game.

Why this matters to SME’s

If you’re in the care sector, or managing building services for example, you know how critical your systems are. Resident records, compliance documentation, scheduling tools, and financial data are how your business operates.

Attackers know that too. Smaller organisations, especially those with limited IT budgets, are often seen as easier targets. The assumption is you’re less likely to have robust defences in place.

The effects are huge. Care teams unable to access patient records, engineers locked out of job schedules, or sensitive data leaked online. The reputational damage alone could take years to repair.

What can you do right now?

The FBI’s guidance is nothing new. But it’s worth acting on today as it’s the best practice, and the same advice we give our customers, to keep unwanted hackers out of your systems:

• Patch everything: Keep your software and systems updated to close off known vulnerabilities.
• Enable multi-factor authentication: That extra login step can stop attackers in their tracks.
• Use web filtering and firewalls: Block access to malicious sites before anyone clicks.
• Segment your network: If one part is compromised, it won’t take the whole business down.
• Invest in threat detection tools: Early detection is your best shot at stopping an attack before it spreads.

Yes, it might sound technical. But the cost of prevention is a fraction of the cost of recovery. And no one wants to explain to clients or regulators how their data ended up on the dark web.

Final thought

The FBI doesn’t issue warnings like this for fun. Interlock is active, aggressive, and evolving. Now is the time to review your defences and make sure your business isn’t next on their list.

Need help figuring out where to start? Let’s talk.