for either Potentially Unwanted
Application Classification used
by anti-malware software
vendors for software
which is not purely malicious like a computer virus or worm but performs undesirable activities such
as tracking users or activities of questionable benefit, such
up the system by an order
Alternately, might stand for Potentially Unsafe Application, a class of programs which perform legitimate activities in the hands of certain personnel, but can be abuse for malicious activity.