This is likely to be a false positive (assuming the installer was downloaded from one of our sites). We are careful to scan all of our installers for viruses. There has never been an incident where one of our installers turned out to be infected with a virus
Some anti-virus software prevents the downloading of executable files unless they are from well-known software companies (such as Microsoft).
If your anti-virus software prevents the download or removes the downloaded file you may have to temporarily disable the auto-scan and try again. If you are worried about this you can always scan the installer after you have downloaded it.