Macintosh Virus Software?

Please do follow the instruction reset safari. To reset safari, choose Safari > Reset Safari.
Verify that your computer isn't configured to connect through a proxy. Choose 'Safari'>'Preferences'>'Advanced'>'Proxies'
In a typical setup none of the items in the left column should be checked.
While you're in there, click on the DNS tab and set your DNS servers to 208.67.222.222
those are the ip addresses for opendns. If this fixes the problem on your computer, then you may want to consider downloading Firefox, using the 'No-Script' add-on, and not using Safari. The best malware protection on a Mac is consistently applying updates as they are put out there. Once every day or two I manually click on the Apple logo in the top-left of the screen and then click on 'Software Update'.