Even if you find a working download, using a cracked service tool can:
A: Legally, yes. The Magnuson-Moss Warranty Act (US) says you can repair your own device, but using unofficial software like ST 5510 gives Canon legal grounds to deny service. Canon Service Tool St 5510 Free Download
If the tool fails or causes errors, you cannot call Canon or any reputable technician for help. You are entirely on your own. Even if you find a working download, using