We present Malicious Email Filter, MEF, a freely distributed malicious binary filter incorporated into Procmail that can detect malicious Windows attachments by integrating with a UNIX mail server. The system has three capabilities: detection of known and unknown malicious attachments, automatic propagation of detection models, and the ability to monitor the spread of malicious attachments. The system filters malicious attachments from emails by using detection models obtained from data-mining over known malicious attachments. It leverages research in data mining applied to malicious executables which allows the detection of previously unseen, malicious attachments. These new malicious attachments are programs that are most likely undetectable by current virus scanners because detection signatures for them have not yet been generated. The system also allows for the automatic propagation of detection models from a central server. Finally, the system allows for monitoring and measuremen...
Matthew G. Schultz, Eleazar Eskin, Erez Zadok, Man