Don’t be surprised to see a new Microsoft Defender entry in your Windows 10 or 11 Start menu if you’re a Microsoft 365 Personal or Family subscriber: the software giant now includes the app, which it says is complementary to the security protections in Windows, in the Office desktop apps installer.

“Starting in late February of 2023, the Microsoft Defender app will be included in the Microsoft 365 installer for customers with active Microsoft 365 Personal or Family subscriptions,” a Microsoft support document explains. “That means that when you install the Microsoft 365 apps on your Windows device, the Microsoft Defender app will automatically be installed for you along with the other apps.”

The document also notes that those with an active Microsoft 365 Personal or Family subscription who have already installed the desktop apps will automatically get Microsoft Defender as part of the next update. I’m seeing it on all of my PCs now, that update must have shipped in the past week or so.

Microsoft began publicly testing the Microsoft Defender app in February 2022 and it went out of preview in June 2022. But now it’s just part of Microsoft 365, and is also available on macOS, iOS, and Android for some reason.

So what is this thing? According to Microsoft, Microsoft Defender is an all-in-one security app that makes it easy to monitor the security status of your PC and devices as well as those used by your family members. It provides antivirus, phishing, malware, spyware, and ransomware protection, identity theft monitoring, real-time alerts with recommended actions, and a dashboard with tips. It’s automatically updated continuously.

There are some caveats. I believe Microsoft Defender is only available to Microsoft 365 subscribers in the U.S. And it is not available on Windows on Arm-based PCs (yet?).

I guess I don’t have any major issues with the app or its functionality, but tying improved security and privacy protections to a paid service is as much a problem today as it was back in the early 2000s when Microsoft launched Windows Live OneCare: this product, like OneCare, overcomes limitations in the protections provided by Windows and should thus be included in the base OS. (Since Microsoft doesn’t own or control the other platforms, requiring a Microsoft 365 subscription for mac, iPhone, or Android usage is another story.)