A computer virus is a little program written especially to do a certain task on a computer with a known operating system and known weaknesses. If you tried to run the virus program on a mobile phone, it probably will not work, as most viruses are written for just one OS. Computer viruses
don’t evolve by themselves so it’s unlikely that viruses will be able to infect operating systems other than that which they are written for. As many newer phones are actually tiny computers, running a variant of UNIX, they benefit from the robust security that the OS is famed for. There are viruses
especially for mobile phones, but these do not spread rapidly because we do not all have the same software on our phones. Soon enough crackers will try and write more viruses for mobile phones and the manufacturers will have to ensure they create software to protect the users.