First, you should know what a botnet is (See my post here).
AVG has a great short list in a good, but long article on botnets. Here are their recommendations to keep you from being part of a botnet:
- Don't download things you don't trust
- Don't click online ads
- Don't fall for phishing emails
- Keep a powerful AntiVirus on your computer
So what do you do if it's too late? What if your computer is showing the symptoms of being part of a Botnet (See blog post here).
- Reset your computer to factory settings
- Scan your computer with a Bootable AntiVirus (I use Kasperky's).
There's also something really comforting that the folks at AVG wrote, "That said, don’t worry too much about it. The average botnet infection has a lifespan that a housefly would pity, with 58% of infections lasting less than a day, and only 0.9% of them lasting longer than a week. So don’t rip out your hair out over it." But this of course requires you to have a good AV on your computer that's current!