Sending automated clicks to ads arguably meets all the elements of common-law fraud:
(1) A false representation of fact (that the user clicked on the ad);
(2) Knowledge of the falsity (by the user installing and using the extension);
(3) Intent to deceive the party by making the false representation (that is the extension's stated purpose!);
(4) Reasonable reliance by the innocent party (by believing the "click" was real and intended);
(5) Actual loss suffered (by paying the owner/operator of the page containing the ad)
In my view, therefore, "fraud" is an applicable term.