Hand Held Hack is a light world warp zone in The Forest (Chapter 1). It is found in 1-19 "Intermission". It is a bandage warp zone, containing two bandages, one on level 2, the other on level 3. It is in Gameboy style (4 color).
Hand Held Hack is a Forest warp zone, so it is quite easy. The first level involves simple climbing and blade dodging; the second level involves going thorough a maze fast as a blade shooter slowly destroys the bottom platform (To get the bandage you have to be really fast); and the third level involves jumping over sawblades and shooting sawblades. View a video walkthrough here.