The links for the mod files are definitely compromised but the link for the launcher seems safe, I'd still be cautious though. Instead I recommend downloading a pixelmon modpack off Technic and taking the mod from that pack, probably the safest bet right now.

Does Pixelmon reforged have a virus?

No it doesn't cause a virus.

Is Pixelmon reforged better?

Pixelmon Reforged

Both versions of the popular Pokémon mod offer a great experience, although Generations offers slightly more updates to the content on a regular basis and has more 7th gen Pokémon than Reforged. Although Reforged is undoubtedly smoother, they both offer a very authentic Pokémon experience.