Malware scanner.

Perhaps the message is coming from one of those popular "fake scanner" malwares that pretend to be a scanner but are really just ransomware/junkware.  But that's just a guess at this point.

What may help shed light on this is when does the message appear?  Is it only when you first login after a reboot? There's a lot of what you might call "entry points" to auto-starting a program at login/bootup. The Start menu "startup" folder for example, but also several places in the registry, or task scheduler, and more.  Windows 8 and higher surfaces most of these on the "Startup" tab of Task Scheduler (Ctrl-Shift-Escape), but in Windows 7 you can get almost the same list by running "MSCONFIG" and checking the startup tab there.  Try to identify anything that shouldn't be auto-launching at bootup, or anything you don't recognize that might be this mysterious malware scanner.  It might need to be a case where you use process of elimination by disabling items, rebooting, and seeing if the message returns.