Password theft is the unauthorized capture of login credentials, such as usernames, passwords, session tokens, or password-manager data, for later reuse or resale. Attackers may steal credentials by phishing, keylogging, fake login pages, malware, browser credential theft, or screen hijacking that hides the real interface while a victim types sensitive information.
In cyber security, password theft matters because a valid credential often bypasses many perimeter defenses. Stolen passwords can be used for account takeover, lateral movement, data exfiltration, and privilege escalation, or sold to other criminals as part of initial-access markets. Defenders reduce this risk with multi-factor authentication, phishing-resistant login methods, strong password hygiene, endpoint protection, credential monitoring, and rapid password resets after suspected compromise.