Backdoor Attacks: Types and How Hackers Exploit Them

A backdoor is a hidden vulnerability or a method of bypassing a website’s normal authentication procedures that allow access to that system. A backdoor attack is a type of cyber attack in which a hacker gains unauthorized access to that system. Although they are technically a virus and a kind of Trojan attack, backdoors aren’t designed to be destructive. They don’t purposefully cause damage to the targeted site. Rather, they provide access to the site, which attackers can use to do whatever kind of damage they want. There are actually three types of backdoors, and not all of them are malicious. Hackers can access the code of a website and add a backdoor that didn’t previously exist, or they can inappropriately access and exploit an existing backdoor’s vulnerability. Backdoors generally fall into one of three categories. The law requires network developers to include these backdoors to provide lawful interception of data. When a law enforcement or government agency gets a court order or a warrant for information from a website, these backdoors allow quick and reliable access. Developers know about these backdoors, and they are protected like any other part of the design code. Many national governments around the world require these backdoors. In some circumstances, an individual or group may get temporary access to a backdoor so that they can assist in the set-up, updates, maintenance, or repairs of networks. A great example is the telecommunications industry, which the law requires to operate with “The Five Nines” in mind. That means that they must provide network connectivity to their customers 99.999% of the time. In order to do so, they sometimes need to allow temporary access to support staff so that they can resolve issues with as little disruption as possible. When people get backdoor access to a network, the security team watches them closely and logs their every keystroke . This is the type of backdoor that is concerning to internet users, web developers, network administrators, and more. A malicious backdoor exists to steal data, take advantage of system vulnerabilities, and potentially access, delete, or alter private consumer or industry data. These backdoors are incredibly useful for hackers and cybercriminals, because they are difficult to detect and provide the attacker with remote control of the site through VNC (Virtual Network Computing) . Some of the ways that hackers can use these backdoors include: This is not a comprehensive list, but it should give you a good idea of how damaging backdoor access can be. Hackers can create backdoors in a variety of places. They choose where to embed their backdoor based on where it will be the least conspicuous, and therefore, less likely to be detected. These locations include: Hackers can create a malicious backdoor by hacking a piece of code, or they can exploit poor coding practices or undisclosed manufacturer backdoors. They can be installed through malware, rootkits, or simply by taking advantage of unpatched vulnerabilities in any system. Advanced persistent threat (APT) groups often use backdoors as part of a multi-stage attack. Backdoor attackers try to mask their presence, and they design their backdoors to evade detection by security software. Sometimes, only a specific command or very specific circumstances will reveal them. Common backdoor techniques include stealthy remote access trojans (RATs), web shells on web servers, debug interfaces that have been left open, undocumented accounts, and covert communication channels. Developers are responsible for providing safety to a number of groups: their employers, people browsing their website or application, and clients and users who share their data with the web application. That means that one of their responsibilities is to prevent attackers from utilizing existing backdoors or adding their own to a vulnerable piece of coding. These are some of the ways that developers and coders should strive to keep their applications from providing backdoor access to cyber criminals: When you suspect that there has been suspicious backdoor activity in your web application, you need to act quickly to ensure the security of your work. This 11-step process will help you determine what you should do when you suspect that a cyber criminal has added backdoor to your system. Take note that many of these strategies for removing a backdoor from a system require a complete rebuild – from scratch. Although patches can sometimes be effective, it is more likely that you will need to start over with a variety of systems in order to get rid of the malicious backdoor. Backdoors provide cybercriminals with stealthy and persistent access to systems and data, making them a serious threat to individuals, businesses, and governments alike. While not all backdoors are illicit, malicious actors can insert backdoors practically anywhere. They’re designed to evade detection through obfuscation techniques. Defending against backdoor attacks requires constant vigilance through preventative coding practices, system hardening, access control, and monitoring for anomalies. If you suspect a backdoor, act swiftly to remove it by reinstalling software, replacing potentially compromised components, changing credentials, and inspecting systems thoroughly. With diligence and layered security, organizations can protect themselves against the menace of backdoor attacks that target their critical systems and sensitive data. While backdoors will continue to pose a risk, following security best practices provides the greatest chance of detecting and mitigating these covert and dangerous threats.