Trend Micro is reporting that spammers have found a new way to attack-networked printers. The attack, called Cross Site Printing for Spamming, relies on a built in, rarely used feature om such printers. They listen on port 9100, a permanently open and non-authenticated port. Once hackers trick users into visiting a malicious site, designed to capture the printers IP address they would be able to connect to it and launch a print job to send spam or gibberish messages, send a fax, reformat the printer's hard drive and more. Researchers say the hackers can accomplish this with a simple iframe. They recommend password protecting networked printers. You can access an excellent presentation about this new form of attack here.