A reverse shell is a cybersecurity technique where a compromised computer initiates a secret connection back to an attacker's system. This allows the attacker to remotely control the infected device, bypassing many security measures like firewalls. Unlike traditional attacks where the hacker connects directly to a victim, a reverse shell reverses the process, making detection harder. Attackers use reverse shells to execute commands, steal data, or install malicious software on the target machine. This method is commonly employed in cyberattacks after an initial breach to maintain ongoing access and control.