Sorry to hear about your Credit Card Dude. Credit Card theft these days are rarely system oriented to the end user but it does happen.
As far as scanning and getting a general feel of your issues I'd encourage you to look into OpenVAS. As KaOS is an independent OS a lot of scanning tools for viruses and vulnerabilities aren't going to work on it because of how they match to the system(s) and version information. That said you can configure OpenVAS to check each binary, file, and hash in the system Takes a bit more time but can get you a decent amount of information.
Please note my recommendation is not official. Just my personal opinion.