About 20 years ago I remember it was semi-common for binaries compiled with anything other than MSVC to be flagged as false positives by other AVs (I suspect if MS had its own AV at the time, it would definitely raise antitrust allegations...) Lots of beginners using GCC (MinGW and the like) complained why their freshly-compiled Hello World executable would disappear without doing anything as soon as they ran it.