Backdoors are an essential part of targeted attacks, as they allow an external threat actor to exercise control over any compromised machines. These allow the threat actor to collect information and move laterally within the targeted organization.
Our investigations into various targeted attacks have showed that a wide variety of tactics are used by backdoors to carry out their routines, as well as remain undetected by network administrators and security products. Over time, these techniques have evolved as more sophisticated defenses become available to network administrators.
more here............http://blog.trendmicro.com/trendlabs-security-intelligence/backdoor-techniques-in-targeted-attacks/
Our investigations into various targeted attacks have showed that a wide variety of tactics are used by backdoors to carry out their routines, as well as remain undetected by network administrators and security products. Over time, these techniques have evolved as more sophisticated defenses become available to network administrators.
more here............http://blog.trendmicro.com/trendlabs-security-intelligence/backdoor-techniques-in-targeted-attacks/