Puzzled by browser redirects
We have several computers on a home network. We have noticed in the last couple of weeks that when trying to access the U.S. sites of Costco and Ticketmaster that sometimes, but not all the time, we have been redirected to Mexican sites of the same companies. We have tried to check for malware and rootkits but have not uncovered anything. Is there something else that could be causing this behavior? We have one PC running Windows 7 and Linux (from a USB drive) and another PC running Windows 8. This redirection has occurred using Google Chrome, Firefox, and Internet Explorer.