"For malicious computer hackers and virus writers, the next frontier in mischief is the mobile phone.
"A phone virus or "Trojan horse" program might instruct your phone to do extraordinary things, computer security experts say.
... "If a malicious piece of code gets control of your phone, it can do everything you can do," said Ari Hypponen, chief technical officer of Helsinki-based F-Secure Corp., a computer security firm. "It can call toll numbers. It can get your messages and send them elsewhere. It can record your passwords."
"As cellular phones morph into computer-like "smartphones" able to surf the Web, send e-mail and download software, they're prone to the same tribulations that have waylaid computers over the past decade.
... "In Japan, deviant e-mail messages sent to cell phones contained an Internet link that, when clicked, caused phones to repeatedly dial the national emergency number -- equivalent to 911. The wireless carrier halted all emergency calls until the bug was removed.
"In Europe, handsets' short message service, or SMS, has been used to randomly send pieces of binary code that crashes phones, forcing the user to detach the battery and reboot. A new, more sinister version keeps crashing the phone until the SMS message is deleted from the carrier's server.
"In the United States, relatively primitive cell phone technology keeps users immune from such tricks, for now.