The advances being made by malware authors and crimeware gangs are keeping them well ahead of the curve. Researchers from Trustwave showed demonstrations of several pieces of custom malware that they d run across in incident investigations in the last year. Some of the attack tools had been on the systems for several months, siphoning off credit and debit card data. The attackers are now intent on keeping control of a compromised system for as long as possible and finding new and interesting ways to stay hidden all the time.
Source: https://threatpost.com/persistent-covert-malware-causing-major-damage-072810/74270/