Windows defender saying Virus protection is out of date

So I woke up at 4am turned on my monitor saw that the last update for windows defender was at 5pm yesterday. I got a notification saying this



So I open defender and see that at 4:17am it had been automatically updated. I clicked this notification and it took me to the update screen and it said security intelligence is up to date I did confirm it was the latest version from the MS page 1.461.26.0 Strange..

I turned on my laptop which hadn't been on in over 12 hours and I remember checking for updates yesterday because I always do on patch Tuesday. Upon start up it gets the same notification but this time when I clicked it the definitions were out of date by abut 12 hours. So it updated them.

I am new to defender. I only just uninstalled Norton a few months back. This is strange behaviour.

Why is it telling me definitions are out of date when they are not.

Mine did that earlier, there was an update to the Antimalware platform today. The error triggered while that was updating.
It's been fine since.

I do not use Windows Defender, but my theory is that is has a "last checked for updates" timestamp and once that passes a threshold it likely sends you a notification. Beyond that I would note signature based detections are good for low hanging fruit threats and not much else. Defender does also rely on heuristics and behavioral detections and are much more useful that signatures.

neemobeer said:

I do not use Windows Defender, but my theory is that is has a "last checked for updates" timestamp and once that passes a threshold it likely sends you a notification. Beyond that I would note signature based detections are good for low hanging fruit threats and not much else. Defender does also rely on heuristics and behavioral detections and are much more useful that signatures.

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It had only been 12 hours since the last update

BrianInEngland said:

Mine did that earlier, there was an update to the Antimalware platform today. The error triggered while that was updating.
It's been fine since.

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Since same thing happened to you means I don't have anything to worry about :) Thank you so much.

JamesSmith said:

Since same thing happened to you means I don't have anything to worry about :) Thank you so much.

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I got the same notice this morning on two of my machines as soon as they booted up. Clicking on the notice opened Windows Security to click the protection update button. Course you can just do Windows Update as will.

Does this happen often?

I thought this type of warning would appear after days of not updating not hours.

JamesSmith said:

Does this happen often?

I thought this type of warning would appear after days of not updating not hours.

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I wouldn't say it's common for overnight but Defender has been kind of quirky on recent builds.