An Avast Hardened Mode pop-up let me know it prevented an .EXE file from starting.
The thing is, it's a file I had just downloaded but I did not try to run it.
I didn't set any browser settings to auto-execute anything, either.
I only noticed the issue with that file, not with other files.
The file comes from the developer's site, and Virus Total says it's clean.
I guess the file is safe but still unknown to Hardened Mode.
What I don't get, though, is why Avast "prevented it from starting", while I did not try to start it.
Happens both in Chrome and Firefox.