I worry that claiming the file contains malware and "will damage your computer", when it does not and will not, reduces how seriously users take those messages.

I worry that claiming the file contains malware and "will damage your computer", when it does not and will not, reduces how seriously users take those messages. This kind of message should be reserved for when malware has actually been detected. Would be fairer to say that the file is untrusted or potentially compromised.