Hackers Hit Microsoft 365 Through ConnectWise: What It Means for Your Business

Robert Moore · 2026-10-17

You know that uneasy feeling when a service you trust suddenly goes dark? That's what happened to ConnectWise customers this week. The company pulled the plug on its Cloud Backup service—formerly known as SkyKick Cloud Backup—after hackers slipped in through application identities and compromised Microsoft 365 tenants. If you're an IT pro or a business owner relying on Microsoft 365, this one hits close to home. ### What exactly went down? ConnectWise didn't just have a minor hiccup. Attackers managed to access application identities, which are basically the digital keys that let different software talk to each other. Once inside, they compromised Microsoft 365 tenants—meaning they could potentially reach emails, files, and whatever else lives in those accounts. ConnectWise's response? Shut down customer access to the backup service entirely. That's like locking the doors and throwing away the key while you figure out who's in the building. ### Why application identities are the new front door Gone are the days when a stolen password was the biggest worry. Application identities often have broad permissions and rarely get the same scrutiny as user accounts. They're like the service entrance that nobody watches. Hackers love them because they can fly under the radar. This supply-chain attack shows just how vulnerable those connections can be—especially when they're tied to critical services like cloud backups. > "The most dangerous backdoor is the one you forgot you left open." ### What this means for you If your business uses Microsoft 365, you're probably wondering: am I exposed? The short answer: it depends on your setup. But here's what you can do right now: - **Audit your application identities** – Review every app that has access to your Microsoft 365 environment. Remove any you don't recognize or no longer need. - **Enable multi-factor authentication (MFA)** – Even for service accounts. It's not foolproof, but it raises the bar. - **Monitor backup services** – If you use third-party backup tools, check their security posture. Ask questions. Don't assume. - **Have a fallback plan** – If your backup service goes offline, can you still recover data? Test your disaster recovery plan. ### The bigger picture Supply-chain attacks aren't going away. They're getting more creative. ConnectWise's move to cut access was drastic but necessary—and it's a wake-up call for everyone. Your security isn't just about your own walls; it's about every service you connect to. So take a hard look at those integrations. The next breach might not come through a phishing email—it might come through a trusted partner. Stay safe out there.