Malware: Fighting Malicious Code

Summary

Backdoors are programs that allow attackers to gain access to a system, bypassing normal security controls. Backdoors allow the attacker to access a system on the attacker's terms, not the system administrator's. The word backdoor is not synonymous with Trojan horse, although people frequently confuse the terms. Trojan horse programs, which are covered in the next chapter, appear to have some benign or even beneficial purpose.

Backdoors can be used for remote execution of individual commands, to gain a command shell on a target system, or even to control the GUI of a victim machine remotely. Using a backdoor, an attacker attempts to maintain control of a victim machine. Attackers often install backdoors after exploiting a misconfiguration ...