What is a malicious entry point that allows unauthorized remote access to a computer or application?

A backdoor serves as a malicious entry point, enabling unauthorized remote access to a computer or application. This method often bypasses regular authentication mechanisms, allowing an attacker to gain control over the system without the knowledge or consent of the legitimate user. Backdoors may be deliberately installed by malware authors or can be created by exploiting vulnerabilities within software or operating systems. Once established, they can provide attackers with ongoing access even after other forms of security measures are put in place, making them a significant security threat.

In contrast, other options are distinct types of malware or security threats. A Trojan disguises itself as a legitimate application to trick users into installing it but does not necessarily create a backdoor unless it has that functionality. A worm is a self-replicating program that spreads independently across networks but does not specifically focus on providing unauthorized access in the way a backdoor does. A rootkit is a set of tools used to hide the presence of other malicious software, enabling attackers to maintain control over a system without detection, but it is not itself an entry point. Each of these has different characteristics and impacts on security but does not specifically fulfill the role of providing a direct entry point for remote access as a backdoor does.