Provided by Aanval (Snort & Syslog Intrusion Detection and Correlation Engine) www.aanval.com
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GEN:SID | 1:796 |
Message | Virus - Possible Worm - xls.vbs file |
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 It has been superceded by sid 721.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 an EXCEL spreadsheet - e.g. businnesplan.xls.vbs gets displayed as businessplan.xls but is a visual basic script and not an EXCEL spreadsheet. |
Affected Systems | |
Attack Scenarios | Famous worms (ILOVEYOU, KOURNIKOVA) are based on this method. Warning: An EXCEL spreadsheet is in now way more secure than a visual basic script. Wrongly configured antivirus software my ignore this files and let a macro virus pass. |
Ease of Attack | Very easy. One needs to attach a file and hope that it gets executed. |
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. |
Additional References | See websites of antivirus companies. |
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DID:730690
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