Uh are you sure you were downloading from a safe site? Check the https:// before www. on a link to ensure it is safe. And yeah use an antivirus(Like Avast , Malwarebytes) And yeah Pop up blockers as extensions are good too to pop up those annoying Ali Express ads and etc. Yeah and obv (not trying to be mean , forgive me if I sound like) but use common sense and stay away from fishy looking sites. Just so you know the optifine REAL webpage link is : https://www.optifine.net/home
(note the https:// meaning its secure) Yeah and stay away from re-directed pages they are mostly scam.

I hope you follow these tips to stay safe online.

This is why you always download from optifine.net

Whatever site you downloaded it from, do NOT trust it for anything anymore. Always use a virus scanner to check files from new and unknown sites.
When downloading a file, make sure to turn on an adblocker so that you're not confused by misleading ads with fake download buttons.

If Optifine gave you a virus, it probably wasn't Optifine. It was more likely that the site you downloaded on was sketchy and ripping the mod and making profit by doing that.

Remember to turn off cookies and turn on Adblock if you have it.

ALWAYS go through the official download site or curseforge.
optifine.net/home

Just use the official website and you should be fine: optifine.net/

Try downloading from a more trusted page, not any pages you don't know of.
Make sure you don't press on anything that isn't the 'download' button. There are a lot of adds on pages for downloadable mods and/or resource/texture packs.
If that doesn't work, I don't know what will.

If you have a Discord I can send you a file, just DM which version.

Discord ID: Vepy#2351

also could you give me the link to optifine HD U I7?

THANKS

I also got a virus from it, and it was the legit website. OptiFine was just not safe for that time. I also got it about 4 months ago.