Wow. That's a bummer. There are actually hundreds of ways this could happen. First off, I'd check to see if your browser configuration looks reasonable, or if this is a network-based attack. Check what your home page is set to in the browser's configuration. Also, look to see if the browser is configured to use a proxy server other than the one you're supposed to be using. It's possible that you surfed to a Web site that passed an evil applet to your machine. The evil applet may have altered your default Web page or browser's proxy configuration. That's how I'd start the investigation.
If that doesn't reveal the problem, I'd double check my DNS configuration in my TCP/IP set up. It's possible that you are set to use a bogus DNS server. Those are the first three of the hundreds of things it could be. If those don't turn up the problem, let me know, and we'll start working on issues four through 100.
This was first published in April 2003