Abstract: A system and method for Uniform Resource Locator (URL) filtering is disclosed. The method comprises receiving an event notification upon the occurrence of an event associated with a received URL; searching, in response to the event notification, a lexical search tree data structure storing a plurality of URLs for the received URL; and processing the received URL in response to the received URL not matching any of the plurality of URLs stored in the lexical search tree data structure.

Abstract: The present invention comprises a method of defining security conditions of a computer system. The method comprises the steps of specifying an identity of attack, specifying at least one attribute of the specified attack, and specifying at least one policy definition with respect to the specified attack, specifying at least one attribute of the specified policy definition.

Abstract: The present invention comprises a method of defining security conditions of a computer system for the purpose of detecting vulnerabilities. The method comprises the steps of specifying a attack representing a recognized vulnerability of the computer system, specifying at least one attribute of the specified attack, specifying at least one policy definition with respect to detecting the vulnerability of the specified attack, specifying at least one attribute of the specified policy definition, and specifying a remedy for the specified vulnerability.

Abstract: A system and method for Uniform Resource Locator (URL) filtering is disclosed. The method comprises receiving an event notification upon the occurrence of an event associated with a received URL; searching, in response to the event notification, a lexical search tree data structure storing a plurality of URLs for the received URL; and processing the received URL in response to the received URL not matching any of the plurality of URLs stored in the lexical search tree data structure.

Abstract: A system and method for searching a signature set for a target signature is disclosed. The method comprises determining a hash value for a target signature; determining a branch associated with a root node of the lexical search tree data structure corresponding to the hash value, the branch along with the root node representing at least one signature of the plurality of signatures, the branch having one or more leaf nodes linked hierarchically to one another, each leaf node representing an element of the at least one signature; and traversing only the branch to find a match between the at least one signature and the target signature.

Abstract: A computer comprising an operating system that controls the computer resources. An intrusion detection system is integrated with the operating system and operable to monitor the computer resources to detect, prevent and report intrusion attempts. An anti-virus system is further integrated with the operating system and operable to detect the presence of at least one virus in the computer resources.

Abstract: A modem is implemented as a virtual device driver with all processing handled by the host computer thus obviating the need for a stand alone processor for the modem. The modem virtual device driver ensures that the modem obtains adequate processing time regardless of other processes running on the host. By combining a port driver directly into the modem contact code, the need for a hardware UART with its attendant limitations is eliminated.

Abstract: A modem is implemented as a virtual device driver with all processing handled by the host computer thus obviating the need for a stand alone processor for the modem. The modem virtual device driver ensures that the modem obtains adequate processing time regardless of other processes running on the host. By combining a port driver directly into the modem contact code, the need for a hardware UART with its attendant limitations is eliminated.

Abstract: DOS application programs are accommodated when using a controllerless modem by providing a virtual device driver. The virtual device driver emulates UART to UART communications and handles interrupts by the DOS applications and by a hardware port managed by the controllerless modem. In one implementation, the virtual device driver shares a communications interface in common with 32-bit applications. In a communication system environment, DOS applications can participate in modem to modem communications with remote DTEs and with other devices using the services of the virtual device driver.