Microsoft Edge and Windows Defender keep flagging the official Electrum downloads as "unsafe"
And I know other antivirus flags it due to "PyInstaller" flagging up as being suspicious activity etc.
I have used the "Report as Safe" option every time this happens, and it still keeps on happening, so I'm fairly sure my reports are being ignored
As for ElectrumABC, they provide sha256 checksums (so you can check file was downloaded OK) and also an archive of the gpg signatures so you can check that it was signed correctly. If all that checks out, then I'd say it was "ok" to use... Given it's on the "official" BitcoinABC, it
should be "legit"... unless the entire project is a "scam"