Could your computer already be infected?
Alureon or TDSS
Alureon (also known as TDSS) is a Trojan and bootkit designed to, amongst other things, steal data by intercepting a system’s network traffic and searching it for usernames, passwords and credit card data.
PCs usually get infected by manually downloading and installing Trojan software, and Alureon has been seen bundled with the rogue security software Security Essentials 2010. When the dropper is executed, it first hijacks the print spooler service (spoolsv.exe) to write a filesystem boot sector at the end of the disk and changing the master boot record to execute this bootstrap routine. It will then infect low level system drivers such as those responsible for PATA operations (atapi.sys) to implement its rootkit. It also manipulates the Windows Registry to block access to Windows Task Manager and the desktop, blocks access to Windows Update and attempts to disable some anti-virus products.