When the customary username or the password is not available either due to forgetfulness or due to some revengefulness of the known members such as the employees who are no more serving etc. it is the backdoor username and password that can open the computer and allow the user to set new customary username and passwords. The manufacturer of computers or software or the developers of software usually create and preserve the backdoor password so that they can access the computer in times of troubleshooting. On the other hand, the cybercriminals often exploit this opportunity and after gaining access to the operating system of the computer they create their won backdoor password so that they can come and go as they please. In some cases, a virus or a worm is used to designate for the purpose of a backdoor which has been created by the attackers during an earlier attack.
There are various types of backdoor operations but broadly can be divided into two basic categories such as legitimate backdoor operation and unauthorised illegitimate backdoor operation. When the manufacturers or the developers create and operate the backdoor passwords they are called legitimate backdoor password operation because they do it for progressive purposes. These backdoor passwords for the purposes of beneficial operations are usually not removed from the production code. On the other hand, backdoors are also popularly used by hackers by putting malware into the backdoor. Eventually, the malware acts as first-line backdoor for the hackers and through this, they can inject as many virus and malware as they wish.
In addition to the above described two types of backdoor operation, the networking protocols and encryption algorithm can be also used as a backdoor operation. The best example for this type of backdoor is the research of 2016 when the white hat researchers revealed that the prime numbers which are used in the encryption algorithm can be crafted to serve the purpose of breaking the encryption and open the way for the adversaries. However, backdoors are very difficult to detect and even if the detection is possible, the ways of detection vary from one computer’s operating system to another. The most popular and perhaps the most easier way to detect the backdoor operation is through the antimalware software. Besides this, the security professionals use protocol monitoring tool or other specialised tools to detect the backdoor passwords.