Malicious backdoors are designed by attackers to avoid detection by traditional security tools such as firewalls, intrusion detection systems (IDS), and anti-virus software. To these security tools, backdoor traffic looks identical to typical application traffic. Mike Puglia from Veracode explains why you need to shut the backdoor. Unintentional backdoors are either introduced due to programming errors or an unawareness of the threat that backdoors present. For example, programmers routinely and purposefully insert a backdoor into an application, in order to access that application later for remote troubleshooting.
