The Dev Team has just posted some type of warning on their blog to alert you of websites claiming to help you jailbreak or unlock your iPhone. Besides messing up your iPhone, these might also infect your computer with viruses.
One very recent example is a certain yellowsn0w221 page on wordpress.com. Do not download anything from that page if you’re on a PC, else you’ll be infected with a virus. The page talks and talks about a supposed Firmware 2.2.1 yellowsn0w exploit, but it’s all a ruse to get you to download and infect your PC.
We’re used to (though still aren’t happy about) less predatory websites, like quickpwn.com. That site (1) is not us. We don’t consult with them in any way (2) makes money from their Google hits (they’re usually near the top) (3) sometimes gives very very bad advice (like tweeting yellowsn0w users to use QuickPwn on 3.0 betas. Bad suggestion). (4) also owns yellowsn0w.net, another money making website.
You can avoid such problems by checking the iPhone Dev-Team official blog or you have got iPhoneheat.com for the purpose.