Arbor Networks, Inc.

A method includes receiving summary messages summarizing respective aggregated traffic metadata packets output from the at least one traffic management device and an engine. Each summary message identifies an origination pair having a traffic management device and an aggregation engine and a sequence number. The method further includes tracking per subinterval of a series of sub-intervals, highest and lowest sequence numbers and a count of summary messages received for each unique origination pair from the beginning of the subinterval. The method further includes accumulating, per interval, accumulated highest and lowest sequence numbers and an accumulated count of summary messages for each unique origination pair from the beginning of the interval and for all previous subintervals for tracking dropped aggregated traffic metadata packets for the interval. The method further includes estimating a number of dropped aggregated traffic metadata packets for the interval based on the accumulated highest and lowest sequence numbers and the count of summary messages.

A computer method and system for determining a threat level score for a detected network attack. Network data is received having a detected network attack, which is then analyzed to determine metadata associated with the network attack. The determined metadata associated with the network attack is analyzed to determine: 1) an attack objective component; 2) an attack method component; and 3) an attack execution component, each being associated with the network attack. A severity score value for the network attack is then determined based upon calculating a weighted value for each of the: 1) an attack objective component; 2) a attack method component; and 3) an attack execution component. And an alert signal/message is then generated for a network attack based upon the determined severity score value.

A method of detecting patterns in network traffic is provided. The method includes receiving packets of network traffic, performing a frequency analysis per field of the packets as a function of frequency of the occurrence of the same data in the corresponding field, and selecting top values which are values associated with each field of the set of fields that satisfy a criterion as having occurred most frequently in the packets as a function of a result of the frequency analysis. The method further includes assigning a bit encoding scheme that uses variable bit encoding to encode each of the top values for each field that has a top value, encoding into a single value each packet of the packets based on a bitfield representation that uses the encoding scheme for values associated with each field that has a top value, storing each potential combination of fields of the set of fields being processed, with all bits set per field when the field is an active field and no bits set when the field is inactive, performing a bitwise operation on each encoded packet with the stored potential combinations, sorting the results of the bitwise operation based on a number of the active fields and a number of occurrences of each same result of the bitwise operation, and providing the results of the sorting to a mitigation device for determining whether an attack is underway and/or for filtering network traffic for mitigating an attack.

A computer system and process for mitigating a Distributed Denial of Service (DDoS) attack by analyzing and correlating inbound and outbound packet information relative to the one or more protected computer networks for detecting novel DDoS Reflection/Amplification attack vectors. Created are separate data repositories that respectively store information relating to captured inbound and outbound packets flowing to and from the protected computer networks. Stored in each respective inbound and outbound data repository are identified inbound destination ports respectively associated with the captured inbound and outbound packets such that each identified inbound destination port number is associated with 1) a packet count relating to the inbound and outbound packets; and 2) a packet byte length count relating to each of the inbound and outbound packets. By accessing the inbound and outbound data repositories, a determination is made as to whether a total inbound packet count for a first inbound destination port is substantially the same to a total outbound packet count for a same inbound destination port. A next determination is then made as to whether a total outbound packet byte length count for the first inbound destination port exceeds a total inbound packet byte length count for the same inbound destination port. DDoS attack mitigation is automatically performed for the protected computer networks responsive to preferably determining 1) the total inbound packet count for a first inbound destination port is substantially the same to a total outbound packet count for a same inbound destination port; and 2) the total outbound packet byte length count exceeds a ratio value relative to the total inbound packet byte length count for the same inbound destination port.

A computer method and system for mitigating Domain Name System (DNS) misuse using a probabilistic data structure, such as a cuckoo filter. Intercepted is network traffic flowing from one or more external hosts to a computer network, the intercepted network traffic including a DNS request that requests a Resource Record name in a DNS zone file. A determination is made as to whether the DNS request is requesting resolution at a protected DNS Name Server. A hash value is calculated for the requested Resource Record name if it is determined the DNS request is requesting resolution at the protected DNS Name Server. A determination is then made as to whether the calculated hash value for the requested Resource Record name is present in the probabilistic data structure. The DNS request is forwarded to the protected server if the requested Resource Record name is determined present in the probabilistic data structure.

A method for detecting patterns using statistical analysis is provided. The method includes receiving a subset of structured data having a plurality of fields. A plurality of value combinations is generated for the plurality of fields using a statistical combination function. Each combination of the generated plurality of value combinations is stored as a separate entry in a results table. The entry in the results table includes a counter associated with the stored combination. A value of the counter is incremented for every occurrence of the stored combination in the generated plurality of value combinations. The results table is sorted based on the counters' values and based on a number of fields in each combination. One or more entries having highest counter values are identified in the results table.

A computer method and system for determining patterns in network traffic packets having structured subfields for generating filter candidate regular expressions for DDoS attack mitigation. Stored packets are analyzed to extract a query name for each stored packet. Each query name is segregated into subfields. A Results-table is generated utilizing the segregated subfields of the query names. A Field-length table is generated that contains the length of the Field Values (Field-length) for each Field Name and an associated counter indicating how many instances the Field-length for a Field Name is present in the extracted query names. The Field-length table is analyzed to determine patterns of equal length in the “Results” table. Utilizing the Patterns table, unique combinations of the Field Values are generated as a filter candidate regular expression for DDoS attack mitigation purposes.

A method of monitoring a network is provided. The method includes receiving a packet of network traffic, determining a source IP address of the packet, consulting a database of source IP addresses, each source IP address having an associated probability of threat indicator (PTI) that indicates a probability of threat posed by the source IP address. The packet's source IP address' PTI is assigned to the packet as the packet's PTI, and one or more inspection checks are selected to be performed on the packet, wherein the selection of the inspection checks is a function of the packet's source IP address PTI. The method further includes performing the selected inspection checks, assigning treatment of the packet based on a result of the inspection checks performed, and adjusting the packet's source IP address' PTI or the packet's PTI based on the result of the one or more inspection checks performed.

Matching an internet service with an IP host address to attribute network traffic to the internet service by mapping one or more server names to an internet service by a network device by detecting a DNS Response to a DNS Query. Inspect the DNS Response to determine an association of a service consumer's IP address with an internet service's server IP address relating to a certain internet service to maintain an array of indexed entries having an association of the service consumer's IP address with an internet service's server IP address relating to a certain internet service for a certain length of time using a probabilistic data structure for the indexed entries.

A computer system and process for mitigating a Distributed Denial of Service (DDoS) attack by analyzing and correlating inbound and outbound packet information relative to the one or more protected computer networks for detecting novel DDoS Reflection/Amplification attack vectors. Created are separate data repositories that respectively store information relating to captured inbound and outbound packets flowing to and from the protected computer networks. Stored in each respective inbound and outbound data repository are identified inbound destination ports respectively associated with the captured inbound and outbound packets such that each identified inbound destination port number is associated with 1) a packet count relating to the inbound and outbound packets; and 2) a packet byte length count relating to each of the inbound and outbound packets. By accessing the inbound and outbound data repositories, a determination is made as to whether a total inbound packet count for a first inbound destination port is substantially the same to a total outbound packet count for a same inbound destination port. A next determination is then made as to whether a total outbound packet byte length count for the first inbound destination port exceeds a total inbound packet byte length count for the same inbound destination port. DDoS attack mitigation is automatically performed for the protected computer networks responsive to preferably determining 1) the total inbound packet count for a first inbound destination port is substantially the same to a total outbound packet count for a same inbound destination port; and 2) the total outbound packet byte length count exceeds a ratio value relative to the total inbound packet byte length count for the same inbound destination port.