fake website generators, where every successive fake site colludes with the rest to boost SEO rankings
automated "news" posts for social media platforms that pay you for advertisements
automated CAPTCHA solving bots set to solving in a "manual" CAPTCHA farm.
self-spreading $XMR miner, launched from the parking lot of a McDonalds 47 miles northeast over the TOR network
creating a fund that stores capital in S&P500, only allowing the current beneficiary to withdraw half the last year's returns. write a book on your philosophies, so when the amount held by the trust becomes sizeable (in a few generations) your lineage and thought patterns will be preserved.
come up with a cool libertarian-esque idea for original tech and ask Peter Thiel for funding. this shouldn't be too difficult, just read a sci-fi book and pick out something that hasn't been done, is interesting, and that you could reasonable solve on a technical level by yourself.