System and method for detecting computer virus

A computer program product for detecting computer viruses, the computer program product comprising a computer usable medium having computer readable instructions therein for causing a processor to perform steps when executed on a computer of an intended recipient of an electronic mail message which:

• examine a message portion of an electronic mail message including the message portion and one or more encrypted attachments, wherein the encrypted attachment is at least encrypted separately from the message portion, the encrypted attachment is of a type for which a corresponding encryption code can be included in the message portion, and the electronic mail message and the encrypted attachment are received together as a combined entity, and the exact location of the corresponding encryption code within the message portion of the electronic mail message is unknown, to identify potential encryption codes;
• use the potential encryption codes to attempt to decrypt one or more of the encrypted attachments;
• and
• if an encrypted attachment is decrypted, scan the decrypted attachment for computer viruses.

A system for detecting computer viruses, said system comprising a computer of an intended recipient of an electronic mail message configured to:

• examine an electronic mail message including a message portion and one or more encrypted attachments, wherein the encrypted attachment is at least encrypted separately from the message portion, the encrypted attachment is of a type for which a corresponding encryption code can be included in the message portion, and the electronic mail message and the encrypted attachment are received together as a combined entity, and the exact location of the corresponding encryption code within the message portion of the electronic mail message is unknown, to identify potential encryption codes;
• use the potential encryption codes to attempt to decrypt one or more of the encrypted attachments;
• and
• if an encrypted attachment is decrypted, scan the decrypted attachment for computer viruses.

A system for detecting computer viruses in an electronic mail message at an intended recipient's computer comprising:

• means for examining a message portion of an electronic mail message including the message portion and one or more encrypted attachments, wherein the encrypted attachment is at least encrypted separately from the message portion, the encrypted attachment is of a type for which a corresponding encryption code can be included in the message portion, and the electronic mail message and the encrypted attachment are received together as a combined entity, and the exact location of the corresponding encryption code within the message portion of the electronic mail message is unknown, to identify potential encryption codes;
• use the potential encryption codes to attempt to decrypt one or more of the encrypted attachments;
• and
• means for scanning a decrypted attachment for computer viruses.