Rule: -- Sid: 795 -- Summary: This rule has been placed in deleted.rules. It has been superceded by sid 721. -- Impact: Mail worms may spread rapidly because users execute them. -- Detailed Information: Windows systems are often configured not to display file extensions. By adding a second extension, users get confused and think that an executable is a text - e.g. loveletter.txt.vbs gets displayed as loveletter.txt but is a visual basic script and not a plain text. -- Affected Systems: -- Attack Scenarios: Famous worms (ILOVEYOU, KOURNIKOVA) are based on this method. -- Ease of Attack: Very easy. One needs to attach a file and hope that it gets executed. -- False Positives: None Known Could be an error on sender's side. -- False Negatives: None Known - -- Corrective Action: Use antivirus software. Configure mail clients securely, especially when using windows desktops. Educate your mail users. Deny all attachments at the gateway if you can. -- Contributors: Original rule writer unknown Snort documentation contributed by tobias.haecker@to.com Sourcefire Vulnerability Research Team Nigel Houghton <nigel.houghton@sourcefire.com> -- Additional References: See websites of antivirus companies. --
