Formbook is a type of malware known as an information stealer. It infects computers, often through phishing emails or malicious downloads, and covertly collects sensitive data such as passwords, login credentials, and other personal information from web forms and browsers. Cybercriminals use Formbook to harvest this data for identity theft, financial fraud, or unauthorized access to online accounts. Its widespread use and ease of deployment make it a common tool in cyberattacks targeting individuals and organizations alike.