What is :WofCompressedData?

Hi:

Also, see here.

Cheers,
MM

Do you think I have anything to be worried about or should I just leave it alone. I see it on both my laptop and desktop, but I find no evidence of viruses or malware on either machine.

My system is not compressed, but I do have System Restore points enabled.

Anyone?

Since this post shows up prominently on Google, I'm going to answer despite the age of this thread. What "WofCompressedData" means is that a file was compressed by Microsoft's command line tool called "compact". It was introduced in Windows 10 back in 2015 and allows you to let Windows compress its own system files. But you can also choose to compress any other folders that you point on it. By default, when Windows notices that your hard disk isn't of big capacity, the system will automatically compress many system files on its own. You can check if Windows decided to do that by opening up a command prompt and typing in

Code:

compact /compactos:query

To help you with your concern, when you see ":WofCompressedData" next to a file during an anti-virus scan, it only means that the specific file was compressed and takes less space on your hard disk. Here is one source that shows you it is really a feature of Windows 10: Yogesh Khatri's forensic blog: WofCompressed streams in Windows 10
Whatever you were told that it is a "file fragment" and that it could be "deleted" is utterly wrong. You were influenced by a false statement from someone who seriously hasn't a real clue themselves.
I understand that finding this odd file name extension made you suspicious, but it is definitely absolutely nothing you need to be worried about. It literally has "CompressedData" in its name, and that isn't made up or anything. So when you see that again somewhere, it only means that the certain file takes up less space on your hard disk.