I have both Web Of Trust and uBlock Origin installed on my browser, I went to download forge for 1.12.1 off of the official website but when I tried to download it uBock blocked adfocus, after I allowed access temporarily WOT blocked it telling me it was known for malware ad phishing. Why are the developers still using this website that's known for these kinds of things and how can I get forge without worrying about getting a virus?
Additionally, the official Forge site has direct download links, they're just a little tricky to find - to the right of each adfocus download link, there's a circled "i" icon that shows the MD5 and SHA1 checksum when you mouse over it, and below that, a direct download link. Clicking the icon will also get you the direct download.
Either use a third party launcher like Twitch, MultiMC (they download it just as easily as getting the files from Mojang's servers for a Minecraft version) or use a modpack launcher like Technic and download a Forge ready with no mods pack.
Or change your web browser settings as it could be preventing it from getting the file as it doesn't trust the site your downloading it from/preventing the download due to the link hosting a jar file, maybe).
I've never had an issue with it on Internet Explorer, Edge or Firefox but I've heard Chrome has/did have it where it prevented the download.