there really is no way to know if you’ve got a virus. it doesn’t take a lot of time to develop a malware that is undetectable, especially if you target something very specific and make it be patient about it. e.g. wait a month, snatch all the browser cookies and send them to a server hosted on azure.
or every so often snatch the clipboard
there are a lot of ways to be very silent
I highly suggest you don’t use the pc you run the pirated games on for anything critical
background: I crack stuff as a hobby (never published anything), used to be a security engineer, programmer by hobby