probably unwanted program (PUP)

A pup is one of those programs that is “piggy-backed” on something that you did not even notice that that you agreed to accept. It is not a virus, so it may have slipped past common virus protection software. Later, they¬†pop up and ask you questions that sound important but do not really matter.

Has this happened to anyone?

(This question came up at the Rainbow Community Center but was not resolved. Will Windows Defender stop probably unusable programs (PUPs)?)