Abstract: Network worms or viruses are a growing threat to the security of public and private networks and the individual computers that make up those networks. A content sifting method if provided that automatically generates a precise signature for a worm or virus that can then be used to significantly reduce the propagation of the worm elsewhere in the network or eradicate the worm altogether. The content sifting method is complemented by a value sampling method that increases the throughput of network traffic that can be monitored. Together, the methods track the number of times invariant strings appear in packets and the network address dispersion of those packets including variant strings. When an invariant string reaches a particular threshold of appearances and address dispersion, the string is reported as a signature for suspected worm.

Abstract: Detecting attacks against computer systems by automatically detecting signatures based on predetermined characteristics of the intrusion. One aspect looks for commonalities among a number of different network messages, and establishes an intrusion signature based on those commonalities. Data reduction techniques, such as a hash function, are used to minimize the amount of resources which are necessary to establish the commonalities. In an embodiment, signatures are created based on the data reduction hash technique. Frequent signatures are found by reducing the signatures using that hash technique. Each of the frequent signatures is analyzed for content, and content which is spreading is flagged as being a possible attack. Additional checks can also be carried out to look for code within the signal, to look for spam, backdoors, or program code.

Abstract: Network worms or viruses are a growing threat to the security of public and private networks and the individual computers that make up those networks. A content sifting method if provided that automatically generates a precise signature for a worm or virus that can then be used to significantly reduce the propagation of the worm elsewhere in the network or eradicate the worm altogether. The content sifting method is complemented by a value sampling method that increases the throughput of network traffic that can be monitored. Together, the methods track the number of times invariant strings appear in packets and the network address dispersion of those packets including variant strings. When an invariant string reaches a particular threshold of appearances and address dispersion, the string is reported as a signature for suspected worm.

Abstract: Detecting attacks against computer systems by automatically detecting signatures based on predetermined characteristics of the intrusion. One aspect looks for commonalities among a number of different network messages, and establishes an intrusion signature based on those commonalities. Data reduction techniques, such as a hash function, are used to minimize the amount of resources which are necessary to establish the commonalities. In an embodiment, signatures are created based on the data reduction hash technique. Frequent signatures are found by reducing the signatures using that hash technique. Each of the frequent signatures is analyzed for content, and content which is spreading is flagged as being a possible attack. Additional checks can also be carried out to look for code within the signal, to look for spam, backdoors, or program code.

Abstract: An apparatus is equipped to receive network traffic data for network traffic routed through a number of routing devices with one or more degrees of separation from a network node. The network traffic data include at least network traffic data for network traffic destined for the network node which meet a traffic type selection criteria and are routed by the routing devices to the network node. The apparatus is further equipped to progressively regulate and de-regulate network traffic routing by the routing devices based at least in part on the received network traffic data and the degrees of separation of the routing devices from the network node. Regulation extends from routing devices with the lowest degree of separation from the network node to routing devices with the highest degree of separation, following in the reverse direction of the routing paths traversed by the packets to reach the network node. In one embodiment, the extension or push back is made one degree of separation at a time.

Abstract: A computer implemented method detects concurrency errors in programs. Machine executable images of multiple program threads are instrumented to locate and replace instructions which affect concurrency states of the threads. Concurrency state information is recorded in a memory while the multiple threads are executing. The recorded concurrency state information is analyzed, and inconsistent dynamic concurrency state transitions are reported as concurrency errors.

Abstract: There is provided a method and apparatus for effectuating data updates on a fault-tolerant storage device having a plurality of disk-drive units forming a disk array, with parity-block updates temporarily suspended to provide increased performance. Parity-block updates are typically deferred until the array is idle. Thus, data is written onto the array with no parity error correction information being present for a short amount of time. Data updates are effectuated by identifying the blocks in the array where data is to be written. New data is then written directly to the identified blocks without reading the old data present therein. A "needs parity rebuild bit" (NPRB) is written to non-volatile memory, identifying the stripes not having parity information on the array. The number of NPRBs present is monitored to allow continuous calculation of a mean-time-to-data-loss (MTTDL). If the MTTDL is acceptable, parity updates are deferred until the array is idle.