Over the past month, a new type of malicious software has emerged, <A HREF="http://www.infoworld.com/article/08/01/09/New-rootkit-uses-old-trick-to-hide-itself_1.html?source=rss&url=http://www.infoworld.com/article/08/01/09/New-rootkit-uses-old-trick-to-hide-itself_1.html">using a decades-old technique</A> to hide itself from anti-virus software. The malware, called Trojan.Mebroot by Symantec, installs itself on the first part of the computer's hard drive to be read on startup, then makes changes to the Windows kernel, making it hard for security software to detect it.