Malware wasn’t always about making a quick buck off the less tech savvy. It was about getting a message across, doing something cool or just down right destroying something that someone loved. They got nothing more out of this than the kicks of writing something.
These days with the Cryptolockers, fake anti-virus programs and all sorts of highjackers they all have an end goal of receiving large sums of money from their victims. The Malware Museum has a showcase of old DOS based viruses that have had their malicious parts removed. You don’t even have to download them. It’s 100% safe.
Check it out over at https://archive.org/details/malwaremuseum