Developers create proprietary backdoors during software development. They don’t usually ship with the final product, but mistakes happen. Cybercriminals can take advantage of these backdoors to attack machines and networks. Malicious third parties, like hackers or cybercriminals (sometimes working on behalf of intelligence agencies) create backdoors to bypass security protocols. They can use backdoors to gather intelligence, take control of systems, or physically damage networks. Backdoors also occur when people don’t follow best security practices, for example, using a weak password to protect sensitive information or skipping two-factor authentication. Cybercriminals can exploit these unintentional security vulnerabilities to access networks and devices.