>I forget where I read it but a not insignificant percentage of pirated software contains malware,

That just means you don't know where to look.

>having my bank or brokerage account compromised would cost exponential orders of magnitude more than any software licence.

I agree. For anything that's important, especially if it's mission-critical or commercial in nature, go the legit way. Handing Microsoft some cash means you're buying legal assurance that something will work safely (FSVO safely) in a way where the chain of liability hopefully doesn't stop at you.