Terrelea Wong's old computer box now sits beside her sofa in the living room, unused, except as a makeshift table that holds a box of tissues.

Ms. Wong, a physician at Kaiser Permanente Medical Center in South San Francisco, started getting a relentless stream of pop-up ads a year ago on her four-year-old Hewlett-Packard desktop computer and a regular message in which her entire screen would turn blue and urge her to "hit any key to continue."

Sometimes, stymied by all the pop-up windows, the computer would freeze altogether.

After putting up with the problem for months, Ms. Wong said she decided last November that rather than fix her PC, she would buy a new one. She said she figured the cost difference would not be much, but she was wrong; succumbing to the seduction of all the new bells and whistles, she spent $3,000 on a new Apple laptop.

Still, she said she was happy to be starting over. In fact, she is instituting new rules to keep her home computer virus-free.

"I've modified my behavior. I'm not letting my friends borrow my computer," she said, after speculating that the indiscriminate use of the Internet by her and her friends had led to the infection of her old computer. "I don't click on any advertisements, and I'm always careful where I click on a page."

A trojan horse is an attack method by which malicious or harmful code is contained inside apparently harmless files. Once opened, the malicious code can collect unauthorized information that can be exploited for various purposes, or permit computers to be used surreptitiously for other malicious activity. The emails are sent to specific individuals rather than the random distributions associated with a phishing attack or other trojan activity. (Phishing is the act of sending an email to a user falsely claiming to be an established legitimate enterprise in an attempt to scam the user into surrendering private information that can be used for identity theft.)

Ryan McGeehan has reported a vulnerability in AOL Instant Messenger (AIM), which potentially can be exploited by malicious people to compromise a user's system. The vulnerability is caused due to a boundary error within the handling of "Away" messages and can be exploited to cause a stack-based buffer overflow by supplying an overly long "Away" message (about 1024 bytes). A malicious website can exploit this via the "aim:" URI handler by passing an overly long argument to the "goaway?message" parameter. Successful exploitation may allow execution of arbitrary code on a user's system when e.g. a malicious website is visited with certain browsers. The vulnerability has been confirmed in version 5.5.3595. Other versions may also be affected.

The BlueSniper "rifle," created by John Hering and colleagues at Flexilis as a proof-of-concept device, resembles a rifle. It has a vision scope and a yagi antenna with a cable that runs to a Bluetooth-enabled laptop or PDA in a backpack. Aiming the rifle from an 11th-floor window of the Aladdin hotel at a taxi stand across the street in Las Vegas, Hering and colleagues were able to collect phone books from 300 Bluetooth devices. They bested that distance and broke a record this week by attacking a Nokia 6310i phone 1.1 miles away and grabbing the phone book and text messages.

NGSS researchers have proven that code execution is possible and that the malicious media file can be activated remotely simply by rendering a specially crafted html document. It has also been discovered that the malicious file does not necessarily need to bear the extension '.xm'. This is due to the fact that 'in_mod.dll' will automatically determine which type of mod media file has been opened by performing certain tests on the file before attempting to load it. The testing is performed by passing the file through all the available loaders to see if one is able to handle it.