Malware writers are getting more and more devious, to prevent you from detecting and/or removing them. You all know about rootkits, that are designed to hide traces of themselves. One of the most recent threats, named Trojan:Win32/Popureb.E, is a bootkit, which not only tries to evade detection but also prevents its code from being changed, to make it harder to clean it off the system. It does this with a driver component. You can find out more of the technical details of how it works here:
About The Author
Debra Littlejohn Shinder is a technology and security analyst and author specializing in identity, security and cybercrime, utilizing her past experience as a police officer and police academy/criminal justice instructor. She has written numerous books and articles for web and print publications and has been awarded the Microsoft MVP designation for fourteen years in a row.