Let me guess. No 2FA?
no viruses...
How would you even know that?
Because I ran a full check with 4 different anti malware / anti virus tools?
That would only protect you from common threats, which the highly specialiced trojans/keyloggers out for bitcoin exchange login data most definitely are not.
The only way to confidently deny the presence of bitcoin malware is if you'd exclusively accessed exchanges via a fresh and clean VM.