See http://www.securelist.com/en/analysis/204792180/TDL4_Top_Bot
The TDL-4 botnet has been said to be 'practically indestructible,' - 'the most sophisticated threat today' Apparently, it has infected over 4 million computers already, many of them in the USA. As I read the article, I was amazed at its sophistication. Very very scary!
