> using a then-popular Windows IDE
If you're referring to Delphi, this has been a common issue for a long time.
Delphi seems to have been very popular with malware writers, and so AV companies keep flagging stuff from the standard libraries as malware.
Got so bad at one time that some tried to get a deal with the major AV players to provide a suite of very basic Delphi applications they could use for false-positive testing.