everyone should read this: Your Apple iPhone could be infected with potentially malicious Trojan software because of a fake upgrade download, computer security officials with US-CERT warned Wednesday. "This Trojan claims to be a tool used to prepare the device for an upgrade to firmware version 1.1.3," the US-CERT advisory said. "When a user installs the Trojan, other application components are altered. If the Trojan is uninstalled, the affected applications may also be removed." The Trojan appears to be timed to exploit rumors that began in early December about new features in an upcoming iPhone firmware upgrade. Various online news sites and blogs cited a report published by CNET France that claimed an imminent iPhone update would feature a disk mode, for using the iPhone as a portable flash drive, and a voice recording mode. Malware authors now regularly craft attacks that play off current news and events. The Storm worm, for example, initially spread through an e-mail message that made reference to what was in January 2007 a recent storm. With the Consumer Electronics Show this week and the Macworld Conference & Expo next week, malware masquerading as an iPhone upgrade will likely dupe more people than it would otherwise. On Monday, Symantec identified the malicious software as "iPhone firmware 1.1.3 prep." In a blog post, Symantec security researcher Orla Cox observes that installing the software doesn't appear to have much of an effect on the iPhone, but warned that uninstalling it could overwrite other iPhone applications. "This is technically the first Trojan horse seen for the iPhone, however it does appear to be more of a prank than an actual threat," said Cox. "The impact of uninstalling the 'Trojan' would appear to be an unintended side effect. The risk to users is minimal as they would have to choose to install the bogus package and the site which was hosting it has now been taken offline. Nevertheless, iPhone users should exercise caution regarding the packages they choose to install on their phones."