Backdoors are security risks that allow attackers to remotely and stealthily access a computer using either plain-text or fully visual interfaces.
Such backdoors are either opened by a Trojan (for instance, the much-hyped Back Orifice remote access tool), or even opened by an existing piece of software on the computer.
Moreover, backdoor features may also be included in commercial software by using a hardcoded combination of username and password. Many times, backdoors are deliberately left open by computer vendors. However, please note that this kind of backdoor is not to be regarded as malware, as it is mostly used for support and maintenance tasks (support staff usually connects to the respective machine remotely, in order to troubleshoot various operation issues).
Still, such backdoors can pose a security risk to the end-user, as they can be easily exploited by unauthorized parties. Unlike spam and Trojans, backdoors don

About the author


Bogdan Botezatu is living his second childhood at Bitdefender as senior e-threat analyst. When he is not documenting sophisticated strains of malware or writing removal tools, he teaches extreme sports such as surfing the web without protection or rodeo with wild Trojan horses. He believes that most things in life can be beat with strong heuristics and that antimalware research is like working for a secret agency: you need to stay focused at all times, but you get all the glory when you catch the bad guys.