Jailbreak rumors, are they true?

So I just jailbroke my iPod and I'm afraid of getting hacked and getting personal info, pwords, and credit card info stolen by hackers... I heard about malicious attacks a worms for jailbroken users and to protect I'm supposed to change my ssh pword in mobile terminal which doesn't work on iOS4 I also heard that if you don't have any ssh app or openSSH then the possibility of getting hacked is not possible... How true are these rumors?