Arbor Networks, Inc.

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 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 method of monitoring a network during a DDoS attack is provided. The method includes receiving packets included in the attack, determining whether the packets are designated for tarpitting, for each packet from a source determined to be designated for tarpitting, assigning the packet to an existing or newly established flow, applying at least one tarpitting technique, and applying a randomization function for adjusting the at least one tarpitting technique or for selecting the at least one tarpitting technique to be applied from a plurality of candidate tarpitting techniques.

A method and apparatus for processing flow specification (Flowspec) messages to one or more of a plurality of customer networks by a controller device coupled to the plurality of customer networks. Preferably a network controller monitors network traffic flowing through each of the customer networks for detecting a network attack in one of the plurality of customer networks, via monitoring of the network traffic. Upon detection of a network attack, a Flowspec message is generated for the customer network detected to be under network attack wherein the Flowspec message is configured specifically for that customer network. The generated Flowspec message is transmitted to the customer network detected to be under network attack for implementation by the customer network for mitigation of the detected network 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 implemented method and system for simulating the effect of one or more flow specification rules upon archived network flow data. Archived network flow data is retrieved from a database that was exported from a network device. One or more flow specification rules are applied to the archived network flow data, wherein the one or more flow specification rules are configured to perform one or more flow specification actions on the archived network flow data. Determined are one or more flow actions affected on the archived network flow data by the applied one or more flow specification rules. Indication/notification of the determined one or more flow actions are provided.

An upstream network bridge connection request is received in a network device from first network component for connecting to a second network component. This upstream network bridge connection request is analyzed by the network bridge to determine if a network attack threat is associated with the client device requesting the upstream network bridge connection to the server device preferably by inspecting certain network metrics present in the downstream connection associated with the client device. If no, then a determination is made as to whether a preexisting upstream network bridge connection between the client device and the server device exists in a connection pool database. If yes, then the preexisting upstream network bridge connection is retrieved from the connection pool database and is implemented for creating an upstream network connection between the client and server devices.

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 computer system and process for mitigating a Distributed Denial of Service (DDoS) attack to one or more protected computer networks by determining keywords and/or patterns in HyperText Transfer Protocol (HTTP) responses. Stored HTTP responses are analyzed to extract one or more HTTP characteristics for each stored HTTP response. One or more patterns having one or more keywords in each stored HTTP response is determined utilizing the extracted one or more HTTP characteristics for each stored HTTP response. A hash value is determined for each determined pattern, which is preferably stored in a hash structure accompanied by its respective determined HTTP characteristics. Each hash value accompanied by its respective determined HTTP characteristics is stored as a mitigation filter candidate if the hash value contains a determined pattern consisting of at least a predetermined percentage of all determined patterns stored in the hash structure. A determination is then made as to whether if each stored filter candidate contains an acceptable pattern, whereby filter candidates having acceptable patterns are removed from being a mitigation filter candidate. A regular expression is then generated for each stored filter candidate adaptable to be utilized as keywords in a DDOS mitigation filter.

A computer implemented method and system for simulating the effect of one or more flow specification rules upon archived network flow data. Archived network flow data is retrieved from a database that was exported from a network device. One or more flow specification rules are applied to the archived network flow data, wherein the one or more flow specification rules are configured to perform one or more flow specification actions on the archived network flow data. Determined are one or more flow actions affected on the archived network flow data by the applied one or more flow specification rules. Indication/notification of the determined one or more flow actions are provided.