When was the last time you seriously asked yourself: “What would happen to my business if all our files were suddenly locked away?”
It’s a frightening scenario — and exactly what the FBI is raising the alarm about right now.
The agency has issued a new security advisory about Interlock, a rapidly growing ransomware group targeting organisations across Europe and North America. If the name is new to you, here’s why you should pay attention.
Who Are Interlock – And Why Are They Dangerous?
Interlock only emerged in September 2024, but they’ve wasted no time becoming one of the more aggressive players in the ransomware landscape. Their victims include a mix of private businesses and critical infrastructure providers — signalling both capability and ambition.
A Ruthless ‘Double-Extortion’ Business Model
Interlock follows the now-common double extortion strategy:
- Break into your systems, often through deceptive or socially engineered methods.
- Steal sensitive data quietly and quickly.
- Encrypt your files, locking you out of your own systems.
- Demand a ransom, usually with a tight deadline (around four days).
- If you don’t pay, they leak your data on the dark web.
This isn’t new, but Interlock is proving particularly fast, organised, and financially motivated.
How Interlock Gains Access To Business Networks
Interlock’s tactics are sophisticated but frighteningly effective:
- Fake browser or security updates designed to trick employees into clicking.
- Booby-trapped websites that automatically install malware.
- Social engineering, exploiting human error instead of technical flaws.
Once inside, they deploy multiple malicious tools that allow them to:
- Steal credentials.
- Spy on activity.
- Move laterally across networks.
- Encrypt files across Windows and Linux environments.
Their cross-platform capability means almost any business could be a target, regardless of size or industry.
Small And Medium-Sized Businesses Are At High Risk
It’s tempting to think ransomware only targets household-name corporations. In reality, SMEs are prime targets, because attackers know:
- Security budgets are smaller.
- Cyber protection tools are often limited.
- Internal expertise may be lacking.
- They’re more likely to pay to avoid disruption.
Imagine losing access to client files, financial records, or core operational systems overnight. Even if you recover data, the reputational damage and downtime can linger for months.
The UK’s National Cyber Security Centre (NCSC) highlights just how destructive ransomware can be, offering clear ransomware guidance for organisations of all sizes.
How To Protect Your Business From Interlock And Similar Threats
The FBI’s guidance aligns with best-practice advice from industry leaders such as the Cybersecurity and Infrastructure Security Agency (CISA) and the NCSC. Here are the essential steps:
- Keep Systems Patched And Updated – Outdated software is a gift to cybercriminals. Regular patching closes known vulnerabilities before attackers exploit them.
- Turn On Multi-Factor Authentication (MFA) – MFA is one of the strongest ways to stop attackers using stolen passwords.
- Use Web Filtering And Firewalls – These help block dangerous sites and prevent malicious downloads.
- Segment Your Network – Don’t let an infection spread like wildfire. Segmentation limits the blast radius.
- Invest In Modern Threat Detection Tools – Advanced cybersecurity tools can spot unusual behaviour and stop attacks before they escalate. This includes:
- Endpoint Detection and Response (EDR).
- Network monitoring.
- Threat intelligence.
- Automated isolation tools.
A Warning Worth Acting On
The FBI doesn’t issue alerts lightly. Interlock is a real and active threat — and their rapid growth suggests they aren’t going away any time soon.
The good news? With the right security measures in place, ransomware attacks become much harder to execute. Acting now is far easier (and far cheaper) than dealing with the fallout later.
If you’re unsure where your business stands, or want support strengthening your cybersecurity defences, get in touch — we’re here to help.
