Jailbreak is not a program. To ''jailbreak'' your iPhone means to unlock its restrictions so that it run apps and software not officially authorized by Apple. It can also refer to unlocking its ability to use any carrier, not just AT&T.
Jailbreaking an iPhone alone will not give it any viruses. However, download unauthorized apps at your own risk.
if you already now it has viruses why ask about it or want it on your phone?Jailbreaking an iPhone