Microsoft has offered antivirus protection with its operating systems as far back as 1993’s Microsoft Anti-Virus for MS-DOS. The current Microsoft Defender Antivirus started life as Microsoft AntiSpyware in 2005.
It was a bumpy ride, with the antivirus tool going through various names and sometimes earning below-zero scores in third-party tests, but with the release of Windows 10, Microsoft Defender Antivirus became a respectable (if not glorious) malware-fighting tool. One consistent factor through all these changes—Microsoft’s protection has always been free.
Is that changing? Many readers were alarmed at the recent announcement of Microsoft Defender for Individuals, which—as Microsoft’s descriptive page makes clear—is only available as part of a paid subscription to the Microsoft 365 cloud-based office service. What happened to free?
Defender of Last Resort
If every PC on the internet has antivirus protection, life gets tougher for malware writers. It’s harder for viruses to spread and less lucrative to plant data-stealing Trojans when most potential victims have antivirus protection. Even ransomware mills can’t strongarm as much money from victims when protection is universal.
That’s why Microsoft designed Defender to power up on any PC that doesn’t have third-party antivirus. Near-universal antivirus provides a kind of herd immunity.
Does it work? Well, Microsoft has the numbers to show it does. Representatives have pointed out that the Malicious Software Removal Tool you see with almost every Windows Update does more than just level up Defender. Unless you opt out, it provides detailed (but not personal) information to Microsoft, including your operating system, any malware detections, and what third-party antivirus may be installed. And studies based on this information show that even unprotected PCs benefit when most of their connections have antivirus.
Defender aims to keep up that herd immunity, without interfering with any user’s choice of third-party antivirus. If you install Bitdefender, Norton, McAfee, or any other recognized solution, Defender suspends its operations, quietly watching from the background. But if you remove protection or (more likely) let it lapse, Defender springs back into action. The point is to keep your system under protection one way or another.
Defender is persistent. To test third-party antivirus utilities without any interference from Defender, I resort to tweaking the Registry, modifying Windows Service permissions, and editing Group Policies. Otherwise, Defender would wipe out some of my samples during the time between starting a new test and completing installation of a new antivirus.
The Microsoft Defender for Individuals(Opens in a new window) announcement starts with a big splash: “Microsoft Defender. Online security, simplified. Easy-to-use online protection for you, your family, and your devices with the Microsoft Defender app, now available for download with your Microsoft 365 subscription.” It caused readers to contact me in a panic. They’ve always relied on Defender (despite my exhortations to use a better free antivirus product). Will they have to change?
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Other mentions in the announcement don’t make things any clearer. For example, “Get one centralized view to manage and monitor your security status across your computers and phones” (emphasis mine). The FAQ answer to “Do I need a Microsoft 365 subscription to use Microsoft Defender?” is a resounding “Yes,” and the FAQ says “No” to “Is Microsoft Defender built into the Windows operating system?”
Windows Users Need Not Worry
In the end, there’s no actual change to Microsoft Defender Antivirus on Windows. The new Microsoft Defender for Individuals strictly protects non-Windows systems. It offers antivirus protection on macOS and Android (but not iOS) and web protection on Android and iOS (but not macOS). Web protection refers to what Windows users know as SmartScreen Filter, which I’ve zinged in the past for protecting only Microsoft browsers.
A blog post by Vasu Jakkal(Opens in a new window), Microsoft’s Corporate VP for Security, Compliance, Identity, and Management, eventually makes it clear that this new offering strictly extends antivirus protection to platforms other than Windows. It doesn’t change the status of Microsoft Defender Antivirus. I should point out that the best macOS antivirus and Android security products almost certainly do a better job. Few are available for free, but then, this new cross-platform Defender also isn’t free.
So, if you’re relying on Microsoft Defender Antivirus for security, nothing actually changes. You can pay to extend protection to other platforms and manage them (and your Windows protection) from one central location. Better yet, you can install a third-party cross-platform security suite to take care of all your devices. But if you do nothing, Defender will still take care of you, as always.
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