US Patent 9467435 Electronic message threat protection system for authorized users

An electronic message threat protection system that incorporates user authorization to ensure that only authorized users receive the benefits of the system's protection. The system protects against threats such as phishing attacks or malware embedded in attached files. References to resources in messages, such as links or attachments, are transformed into protected references that may for example insert a level of indirection between the user and the resource. Use of a protected reference triggers a user authorization check; if the user is an authorized user, the system provides access via a security mechanism that mitigates potential threats. Unauthorized users are denied access. A message recipient may deliberately or inadvertently distribute copies of the message or of the protected references; however, the authorization check ensures that recipients of the copies can only access resources via these copies if they are authorized users.