> I used tiny core to isolate my banking (...) in virtualbox.

A few years ago, I tried something similar—not out of fear that malware might steal money from my bank account, but because my bank required me to install some kind of security software to access their internet banking on a PC. It turned out they don't like customers running their software in VMs. My account was completely blocked, including my debit card and ATM access. I had to visit a physical branch to resolve the issue. So I gave up on using internet banking on a PC and switched to their mobile app instead.