I have a 7 year old iMac, still on Mountain Lion. Yesterday I tried to down load a map, seemed to get an App instead "doctopdf.pronto". I was able to access and print the map, but when I tried safari again, I got "503 service unavailable". Any further enquiries seemed to go to Bing. Also in address line, in grey print, was something called "search Tokyo falcon . com". (I added the spaces). Now afraid to use computer in case of possible virus, so am on iPad. My broadband helpline could not help. Any ideas?