McAfee’s virus scan and similar software will pop-up identifying information when a PUP is encountered and ask for your permission to remove it.
The types of programs most frequently assigned PUP status are spyware and adware, though viruses also fall into this category.
Spyware and adware are both installed on your hard drive without your knowledge. Visiting a site that requires a login can often begin the download process, as can online shopping.
Spyware vs. Adware
Spyware is a small executable program that reports back to the sender which sites you visit as you use the internet. This information can then be used to target your email address for advertisers.
Adware is another small executable that will cause pop-ups and pop-unders to appear on your screen as you move about the web.
Controlling and Removing PUP’s
Most virus protection software will identify PUP’s and remove them. This approach is most effective against viruses and newly-downloaded adware and spyware. For PUP’s that have been in residence on your hard drive for some time, software specifically targeting those types is more effective. It is wise to completely remove the PUP’s even if your software is configured to quarantine for a time before deletion. A PUP that is allowed to remain in place will often become difficult or impossible to remove. One popular free download site has been known to introduce PUP’s that cannot be removed without fatally crashing the hard drive.