Method and apparatus for filtering e-mail infected with a previously unidentified computer virus
First Claim
1. An automated method for filtering electronic mail, the method comprising:
- receiving an original electronic mail message from a sender;
identifying the original electronic mail message as being potentially infected with a computer virus; and
automatically sending a challenge back to the sender, wherein the challenge comprises an electronic mail message which requests a response from the sender, and wherein the challenge has been designed to be answered by a person and not by a machine.
1 Assignment
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Accused Products
Abstract
E-mail which may be infected by a computer virus is advantageously filtered by incorporating a “Reverse Turing Test” to verify that the source of a potentially infected e-mail is human and not a machine, and that the message was intentionally transmitted by the apparent sender. Such a test may, for example, involve asking a question which will be easy for a human to answer correctly but quite difficult for a machine to do so. The e-mail may be deemed to be potentially infected based on an analysis of executable code which is attached to the e-mail, or merely based on the fact that executable code is attached. The e-mail may also be deemed to be potentially infected based on additional factors, such as, for example, the identity of the sender and past experiences therewith. Spam E-mail may also be advantageously filtered together with virus-containing e-mail with use of a single common filtering system.
316 Citations
30 Claims
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1. An automated method for filtering electronic mail, the method comprising:
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receiving an original electronic mail message from a sender;
identifying the original electronic mail message as being potentially infected with a computer virus; and
automatically sending a challenge back to the sender, wherein the challenge comprises an electronic mail message which requests a response from the sender, and wherein the challenge has been designed to be answered by a person and not by a machine. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An automated method for filtering electronic mail, the method comprising receiving a plurality of incoming electronic mail messages;
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identifying one or more of said incoming electronic mail messages as being potential spam;
identifying one or more of said incoming electronic mail messages as being potentially infected with a computer virus;
for each of said incoming electronic mail messages which has been identified either as being potential spam or as being potentially infected with a computer virus, automatically sending a challenge back to a corresponding sender of said incoming electronic mail message, wherein each of said challenges comprises an electronic mail message which requests a response from the corresponding sender of said incoming electronic mail message, and wherein each challenge has been designed to be answered by a person and not by a machine. - View Dependent Claims (17, 18, 19, 20, 21, 22)
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23. An automated electronic mail filter comprising:
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means for receiving a plurality of incoming electronic mail messages;
means for identifying one or more of said incoming electronic mail messages as being potentially infected with a computer virus;
automatic means for sending challenges back to corresponding senders of each of said incoming electronic mail messages which have been identified as being potentially infected with a computer virus, wherein each of said challenges comprises an electronic mail message which requests a response from the corresponding sender of said incoming electronic mail message, and wherein each challenge has been designed to be answered by a person and not by a machine. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30)
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Specification