If you got Blender from a trusted source [the official site - and didn't use any "download helper/manager" programs] then it should be clean/safe. Your antivirus should have a way to make a "rule"/"exception" for or "white-list" a program which would let you tell your antivirus to ignore Blender. That'd be the option I'd probably use.

Alternatively, you could disconnect from the internet and temporarily disable your AV while working with Blender. As long as you've scanned any files on your computer beforehand, and didn't have any issues, that should be safe enough, if a bit of a hassle.

You say its only happening intermittently; if its happening only when working with a specific .blend file, that you may have picked up from somewhere on the net, then that file might warrant a more careful scanning.

Core i7 950@3.02GHz | 12GB Corsair Dominator Ram@1600mHz | 2GB Geforce GTX 660

Lightwave | Blender | Marmoset | GIMP | Krita