I’ll say it again, even though no one likes to hear it: Don’t use third-party anti-virus programs on your computer. They create more problems than they solve and are often useless pieces of crap. Instead, only use the Windows Defender built into Windows, which is turned on automatically for you. It’s plenty good and creates the least amount of problems for you.
Oops, this was supposed to be in reply to the OP, not you Jens, sorry.
Agreed, In my 40 years experience - some of them with sophos antivirus, bullguard, norton, symantec, checkpoint etc. and windows defender since it started – this is the way… (ok, I don’t think the ZX81 had viruses - but that’s even less reason why you would run a third-party AV program :))
I got the same thing with AVG antivirus, this is the first time it was blocking a download, though. It told me “URL Blacklist” - so the download address itself seems suspicious to it this time - maybe the SSL certificate ran out or something? Don’t matter too much, could download it when I switched it off.