When was the last time you stopped and asked, “What would actually happen to our firm if every file we rely on was suddenly locked away?”

For many Michigan accounting, law, and medical practices, that scenario feels distant… until it isn’t. And the FBI just raised the stakes again with a new nationwide warning about a rapidly growing ransomware group called Interlock.

Before we dive into what this means for your Michigan business, here’s a quick video breakdown you can share with your team:

▶ Watch: FBI Issues New Ransomware Warning (What SMBs Need to Know)

Who is Interlock — and why does it matter to Michigan SMBs?

Interlock only appeared in September 2024, but they’ve made fast progress. They aren’t looking for headlines. They’re looking for payouts. Their model is simple and ruthless:

1. Slip into your systems

2. Steal sensitive data quietly

3. Encrypt everything your business needs

4. Demand payment with about a 4-day deadline

5. Threaten to leak your data on the dark web if you don’t pay

This “double-extortion” method has become common, but Interlock is unusually aggressive and capable of hitting both Windows and Linux systems. That means just about any Michigan professional-services firm is in their range.

How they get in: modern deception at scale

Interlock uses tactics that look legitimate to the average employee. Their entry points include:

• Fake browser updates

• Fake security notifications

• Compromised websites

• Tools that steal passwords and help attackers move across your network

One quick click is all it takes.

In Michigan firms, where teams are busy, client deadlines are real, and every minute counts, these attacks blend in easily. Attackers rely on distraction, not negligence.

Why Michigan firms are being targeted right now

Across Detroit, Southfield, Grand Rapids, Troy, Ann Arbor, and the surrounding areas, SMBs are facing the same challenges:

• Compliance expectations are rising

• Cyber insurance renewals are tightening

• Staff are using more cloud tools

• IT budgets are under increased scrutiny

• Remote and hybrid work adds new risk

Cybercriminals know this. They understand that professional-services firms—especially accounting, legal, and medical practices—hold high-value data and often run lean internal teams.

It makes Michigan SMBs an attractive target.

What an attack can mean for your business

Think about your day-to-day operations:

• A law firm suddenly loses access to active case files

• An accounting firm can’t open client financials during tax season

• A medical practice can’t reach EMR/EHR systems or billing data

Downtime is expensive. Loss of client trust is worse. And for firms bound by confidentiality and compliance, the reputational impact can follow you for years.

That’s why this FBI alert matters.

What the FBI is recommending (and how it aligns to CIS Controls v8.1)

The FBI’s guidance mirrors the same standards cyber insurers and compliance frameworks (CIS, NIST, HIPAA) are pushing:

1. Patch and update everything

Most attacks target outdated systems.

2. Turn on multi-factor authentication everywhere

MFA stops the majority of account compromise attempts.

3. Strengthen web filtering and firewall protections

Stops access to malicious sites and downloads.

4. Segment your network

One infected device shouldn’t take down your entire office.

5. Use modern detection tools

EDR, SOC monitoring, and behavior-based alerts catch attacks early.

These steps are not overkill. They’re the new baseline for doing business in Michigan.

What Michigan SMBs should do next

Ransomware is no longer a big-business story. It’s a Michigan SMB story. And Interlock is simply the latest wake-up call.

If you’re unsure where your risk stands or whether your firm meets today’s insurance and compliance expectations, this is the time to close the gaps.

We help Michigan accounting, legal, and medical practices stay protected with simple, effective, business-aligned cybersecurity that keeps your operations running and your clients confident.

Need help keeping your business protected? Let’s talk.