Abstract: A system identifies undesirable content in responses sent to a user, such as in e-mail or in downloadable files, from an Internet or intranet site. The system utilizes a redirection program that identifies content requests from a user to a target server. The redirection program redirects the request to a proxy server that sends the request to the target server. Upon receipt of the response from the target server, the proxy server scans the response, which includes any attachments, for undesirable content, such as junk e-mails, computer viruses, pornographic material, and/or other undesirable content. The proxy server then acts upon the response, and any undesirable content, in accordance with default or user-defined parameters, such as removal of the undesirable content. The proxy server may then send the response, as modified, or a notification message to the redirection program forwarding to the user.

Abstract: A system identifies computer worms associated with published, or otherwise, known security holes. The system uses a worm pattern developed to identify those data packets most likely to be a computer worm designed to take advantage of a particular security hole. The worm pattern includes a portion used to functionally characterize the computer worm and another portion used to provide a defense mechanism used to thwart the worm attack. In some cases, the defense action is truncating the suspected data word, while in other cases, the suspect data word is stored in a buffer for later investigation. In a particular implementation, the worm patterns are retrieved from a worm pattern update server.

Abstract: A system identifies undesirable content in responses sent to a user, such as in e-mail or in downloadable files, from an Internet or intranet site. The system utilizes a redirection program that identifies content requests from a user to a target server. The redirection program redirects the request to a proxy server that sends the request to the target server. Upon receipt of the response from the target server, the proxy server scans the response, which includes any attachments, for undesirable content, such as junk e-mails, computer viruses, pornographic material, and/or other undesirable content. The proxy server then acts upon the response, and any undesirable content, in accordance with default or user-defined parameters, such as removal of the undesirable content. The proxy server may then send the response, as modified, or a notification message to the redirection program forwarding to the user.