Why am I being redirected to other sites? Mac Malware.

Some users experience a problem with being directed automatically to sites that they didn't intend to visit. This may also occur when searching with Google. You don't have a virus! It's a problem with your DNS settings, either in your Mac or in your router. Try resetting your router. Here's how to fix the problem in Mac OS X: 

1. Go to System Preferences > Network
 

2. There you will see a padlock icon in the lower left corner. If the padlock is already open (unlocked), go directly to step 3. If the padlock is closed and the note says "Click the lock to make changes", click the lock and enter your administrator password, so you can change DNS servers.

3. Select your network on the left column, click the "Advanced" button in the lower right area of the window.

4. Click the DNS tab to see the listing of your DNS Servers

5. If any of the DNS servers are greyed out after entering your admin password, you may be able to simply add the OpenDNS or Google servers listed below. If you need to remove greyed-out servers, refer to this: 10.5: Disable DHCP-specified DNS servers
 

6. Select each set of numbers and click the "-" icon for each to remove all existing DNS servers

7. Click the "+" icon to add the following servers.

You may choose either OpenDNS or Google servers (not both sets):

OpenDNS (OpenDNS has announced they are blocking the Flashback trojan):

Primary DNS Server: 208.67.222.222

Secondary DNS Server: 208.67.220.220

Google:

Primary DNS Server: 8.8.8.8

Secondary DNS Server: 8.8.4.4

8. When you've completed your changes, click "OK" to close the Advanced settings window

9. Click "Apply" on the Network window to save your changes

As an alternative, you can use namebench to find the fastest DNS servers available for your computer.