Some people who are strongly anti-core have submitted some binaries of Core to antivirus vendors to list them as viruses in order to discourage people from using Core. Since they probably don't want to go through the effort of installing Core and then uninstalling it, they probably just used the binaries from the zip files. Because the binaries from the zip files are different from the ones in the installer due to NSIS, those are the ones that are flagged as viruses and not the ones in the installer.
If you still think that it is a virus, you can check that it is not for yourself. Checkout the 0.14.0 source code and examine it for yourself that there is no virus in there. Then perform the same gitian deterministic build process and release process for yourself and see if the output matches. The way that gitian works is that it will always produce the same exact binaries for the same exact code (normally the binaries will differ even with the same code due to timestamps and other sources of non-determinism). If it matches, then there is no virus. If it does not match, then either you have done something wrong, or the binaries on bitcoin.org are not legitimate. However, that is likely not the case as the hashes of those on bitcoin.org matches the hashes built by the multiple independent gitian builders.
Your first paragraph would explain things to my satisfaction, if that's what happens. Coins are becoming dirty pool but I guess with billions of dollars at stake it's the same as any business. I'm not going to go through all the technical efforts in your second paragraph but you obviously have some expertise so that works. Thanks.