The new malware, dubbed "iPhone/Privacy.A" by Austin, Tex.-based security vendor Intego, uses the same approach as last week's "ikee" worm to silently snatch control of some iPhones. The attack code then steals a wide variety of personal information from the hijacked iPhone, including e-mail messages, names from the address book, text messages, music and video files, photos and calendar entries.

Slideshow: iPhones and iPods on the Job: Creative Uses

Like ikee, which gained momentary fame as the first iPhone worm , iPhone/Privacy.A attacks only those Apple smartphones whose users have hacked, or "jailbroken" the devices to install unauthorized software or make calls on carriers other than the ones Apple assigns.

The ikee worm was released a week ago by Ashley Towns, a 21-year-old unemployed Australian programmer, who told the IDG News Service that he intended it as a prank.

Towns' worm simply replaced the iPhone's wallpaper with a photograph of 80s singer Rick Astley, to pillage data. His worm accessed others' iPhones using the unchanged default password of the SSH (secure shell) Unix utility, which users had installed when they hacked their iPhones or afterward, after they'd downloaded and installed the utility from Cydia , a directory of unauthorized iPhone applications. SSH lets users connect to their iPhone remotely over the Internet via an encrypted channel.

"It's not surprising," said Charlie Miller, a noted researcher of iPhone vulnerabilities , when asked his take on the move toward malicious intent. "This 'vulnerability' gives you root access to the iPhone, which gives you full access. It's trivial to exploit, doesn't need shellcode or anything like that."

Similar malware could also do more than the data plundering that iPhone/Privacy.A is engaged in, Miller said. "Stealing personal data is certainly possible, as is running up the phone bill, sending bulk SMS messages and so on," Miller added.

According to Intego and other researchers, the new iPhone malware can also be installed on Windows PCs, Macs and even Linux systems, which then act as a base from which to infect nearby iPhones.

"This could easily be installed on a computer on display in a retail store, which could then scan all iPhones that pass within the reach of its network," said Intego spokesman Peter James on the company's blog . "Or a hacker could sit in an Internet caf? and let his computer scan all iPhones that come within the range of the Wi-Fi network in search of data."