Microsoft Application Guard for Office is being ‘deprecated’ (phased out) in Windows 11 and Windows 10 after only a few years. No official reason has been given and the excuses don’t make sense.
Back in 2019 Microsoft announced Application Guard as a new way to isolate macro enabled documents from unknown sources. Suspect documents are opened in a sub-system with restricted access to the whole computer.
The idea was a last line of defense for anyone tricked into opening a nasty document. See What is Application Guard and what it means for Office 365
That was only four years ago. What’s replacing Application Guard? Nothing as far as we can tell. This is all Microsoft has said about the change.
Microsoft hasn’t explained why Application Guard is being dropped. It’s been linked by others to the rise of AI used by hackers to make more complex and undetectable attacks.
If that’s Microsoft’s reasoning, it doesn’t make sense. The whole point of Application Guard was to isolate suspect documents that have slipped past tests of incoming files and tricked the user into opening it.
Now Microsoft says that’s not necessary and recommends their Defender for Endpoint which is a paid security platform for enterprises. In other words, organizations are supposed to pay more to Microsoft for ‘front line’ defense while the company drops the essential ‘last line’ protection.
Also they mention Office Protected View has been available for many years but doesn’t offer the same level of protection and isolation that Application Guard does.
Absent any explanation from Microsoft, the best way to understand their reasons is “follow the money”. Maybe Application Guard was too hard and expensive to maintain? Perhaps organizations were relying on it too much and not spending money on Microsoft security products?
The only good news is that Application Guard is only ‘deprecated’, meaning it won’t be developed further but will still work in Windows 11/10 for some time yet.
Any way you look at it, dropping Application Guard is a net loss for Microsoft’s enterprise customers.
