Just when we thought we had a handle on virus-by-email-attachment. Neither you nor your kids could get your PCs infected by the Sasser worm by opening an email attachment. It just arrives through a port on PCs that aren’t secured with the latest Microsoft patch. “The worm spreads by scanning different ranges of Internet addresses using a specific application data channel, or port, numbered 445,” CNET later reported. It just annoyingly “causes the computer to shut down, then reboot … continuously.” The best prevention measure is to keep up to date with Microsoft patches and your firewall going. CNET explained that “the worms infect vulnerable systems by establishing a remote connection to the targeted computer, installing a File Transfer Protocol (FTP) server and then downloading themselves to the new host.” As of Tuesday, Sasser versions didn’t open a “backdoor” to PCs that would allow spammers and other hackers to take control of them. But PC security experts didn’t rule that possibility out for future versions. Microsoft is considering a plan to automate worm-zapping, Internet News reports.