Two things:
- Going to internet forums for legal advice? Probably not the best source for that.
- There’s no legal recognition of “abandonware”, at least in US and Int’l IP law. There was a push a few years ago to let things move into the public domain if, for example, the owner of rights is a legal entity that has been dissolved. It was not successful. Even if the company isn’t around, there are likely successors in interest who could go after you. Will they? Totally depends, but you’re definitely at risk using someone else’s IP.
Now, there are situations where you might be okay. There are legally recognized exception to copyright, such as fair use and parody, but I doubt any of them will apply to your case and few of them are bright-line and free of risk.