This is 100% legal under fair use (personal backup).
To verify you have the real full album zip, here is the definitive tracklist. Be careful—many old zips are missing tracks 4, 12, or the hidden outro. Black Eyed Peas-Monkey Business Full Album Zipl -UPD-
Fast-forward to the present day, and the album remains a fan favorite. With the rise of music streaming and file-sharing platforms, it's easier than ever to access the album. A quick search online reveals that fans can still download the full album, including the bonus tracks, using a zip file. This is 100% legal under fair use (personal backup)