I'm getting a random notice in the lower right corner of my screen. (Windows 8.1) that says "virus definition files are out of date. you should update them" with a link to update. That's all that's on the notification. The rest is just a white background. I'm afraid to click the link. I'm running the free version of AVG and AVG says it's all up to date. Windows Defender is turned off. I tried a restore point, but it's still popping up.
I ran Malwarebtes and it found some pups which I removed, but I'm still getting the popup.
Any ideas how to tell if this is legitimate? I'm afraid to log into anything secure while on my computer.