IDENTIFICATION OF PATTERNS IN STATEFUL TRANSACTIONS

• US 20130318166A1
• Filed: 08/02/2013
• Published: 11/28/2013
• Est. Priority Date: 12/05/2008
• Status: Active Grant

• Current Assignee: Lookingglass Cyber Solutions, LLC
• Original Assignee: CloudShield Technologies, Inc. (ZeroFox Holdings, Inc.)
• Inventors: Jungck, Peder J., Helms, David
• Granted Patent: US 9,166,942 B2
• Time in Patent Office: Days
• US Class Current: 709/204
• CPC Class Codes: H04L 51/212 using filtering or selective blocking
• CPC Class Codes: H04L 51/23 Reliability checks, e.g. acknowledgments or fault reporting
• CPC Class Codes: H04L 63/0245 Filtering by information in the payload
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 63/1408 by monitoring network traffic monitoring network traffic per se H04L43/00
• CPC Class Codes: H04L 63/20 for managing network security; network security policies in general filtering policies H04L63/0227
• CPC Class Codes: H04L 65/1076 Screening of IP real time communications, e.g. spam over Internet telephony [SPIT]
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04W 4/14 Short messaging services, e.g. short message services [SMS] or unstructured supplementary service data [USSD]

Abstract

A system for the identification of patterns in stateful transactions may include a message interceptor, a message pattern processor, a message handler, and a memory. The message interceptor may be operative to intercept messages transmitted by a first device over a network to a recipient. The message interceptor may be operative to intercept the messages before the messages are received by the recipient. The message pattern processor may be operative to add the message to a message pattern and store the message pattern in a memory. The message pattern processor may compare the message pattern to a plurality of exemplary message patterns and identify when the message pattern matches at least one of the exemplary message patterns. The message handler may be operative to determine an action to take with respect to the message based on the at least one matching exemplary message pattern identified by the message pattern processor.

Claims

1. A method of identifying a pattern in a plurality of messages, the method comprising:

(a) for each message of the plurality of messages transmitted by a first device to a recipient over a network, intercepting the message prior to receipt by the recipient;

(b) adding a descriptor representative of the message to a message pattern;

(c) comparing the message pattern to a plurality of exemplary message patterns;

(d) identifying when the message pattern matches at least one of the exemplary message patterns; and

(e) determining an action to take with respect to the message based on the identifying.

2. The method of claim 1, further comprising:

(f) intercepting a response sent by the recipient to the first device in response to the message, prior to receipt by the first device;

(g) adding a descriptor representative of the response to the message pattern;

(c) comparing the message pattern to the plurality of exemplary message patterns;

(d) identifying when the message pattern matches at least one of the exemplary message patterns; and

(e) determining an action to take with respect to the response based on the identifying.

3. The method of claim 1, wherein the plurality of exemplary message patterns comprise valid message patterns, the action comprising allowing the message to continue to the recipient when the message pattern matches at least one of the exemplary message patterns and preventing the message from reaching the recipient when the message pattern fails to match at least one of the exemplary message patterns.

4. The method of claim 1, wherein the plurality of exemplary message patterns comprise invalid message patterns, the action comprising allowing the message to continue to the recipient when the message pattern fails to match at least one of the exemplary message patterns and preventing the message from reaching the recipient when the message pattern matches at least one of the exemplary message patterns.

5. The method of claim 1, wherein each of the plurality of exemplary message patterns comprises a regular expression.

6. The method of claim 1, wherein the plurality of messages comprises a session initiation protocol.

7. The method of claim 1, wherein the plurality of messages establish a session between the first device and the recipient, the session being characterized by a state, each message of the plurality of messages being capable of altering the state of the session, the identifying further determining when the state of the session changes from a first state to a second state based on the message.

8. A system for identifying a pattern in a plurality of messages, the system comprising:

(a) means for intercepting each message of the plurality of messages transmitted by a first device to a recipient over a network prior to receipt by the recipient;

(b) means for adding a descriptor representative of the message to a message pattern;

(c) means for comparing the message pattern to a plurality of exemplary message patterns;

(d) means for identifying when the message pattern matches at least one of the exemplary message patterns; and

(e) means for determining an action to take with respect to the message based on the identifying.

9. The system of claim 8, further comprising:

(f) means for intercepting a response sent by the recipient to the first device in response to the message, prior to receipt by the first device;

(g) means for adding a descriptor representative of the response to the message pattern;

(c) means for comparing the message pattern to the plurality of exemplary message patterns;

(d) means for identifying when the message pattern matches at least one of the exemplary message patterns; and

(e) means for determining an action to take with respect to the response based on the identifying.

10. The system of claim 8, wherein the plurality of exemplary message patterns comprise valid message patterns, the action comprising means for allowing the message to continue to the recipient when the message pattern matches at least one of the exemplary message patterns and means for preventing the message from reaching the recipient when the message pattern fails to match at least one of the exemplary message patterns.

11. The system of claim 8, wherein the plurality of exemplary message patterns comprise invalid message patterns, the action comprising means for allowing the message to continue to the recipient when the message pattern fails to match at least one of the exemplary message patterns and means for preventing the message from reaching the recipient when the message pattern matches at least one of the exemplary message patterns.

12. A method for the identification of patterns in stateful transactions, the method comprising:

(a) identifying a plurality of exemplary message patterns, wherein each exemplary message pattern comprises a specification describing a sequence of messages for a transaction over a network;

(b) intercepting a message from a first device intended to be communicated over the network to a second device;

(c) adding a descriptor of the message to a current message pattern, wherein the current message pattern comprises a specification describing a sequence of messages associated with a current transaction over the network between the first device and the second device;

(d) determining whether the current message pattern matches one of the plurality of exemplary message patterns; and

(e) one of communicating the message to the second device or preventing the message from being communicated to the second device based on the determining.

13. The method of claim 12 further comprising:

(f) removing the descriptor of the message from the current message pattern if the current message pattern does not match one of the plurality of exemplary message patterns; and

(g) repeating steps (b)-(f).

14. The method of claim 12 wherein the plurality of exemplary message patterns comprises a plurality of exemplary session initiation protocol message patterns.

15. The method of claim 12 wherein determining whether the current message pattern matches one of the plurality of exemplary message patterns further comprises using a regular expression engine to determine whether the current message pattern matches one of the plurality of exemplary message patterns.

16. A method of preventing fraudulent signals in session initiation protocol transactions, the method comprising:

providing a packet monitoring device to intercept a plurality of packets intended to be communicated to a session initiation protocol proxy server;

intercepting the plurality of packets intended to be communicated to the session initiation protocol proxy server;

performing a deep packet inspection on the plurality of packets to identify a session initiation protocol signal;

processing the session initiation protocol signal to determine whether the session initiation protocol signal is fraudulent; and

dropping the plurality of packets if the session initiation protocol signal is determined to be fraudulent, otherwise allowing the plurality of packets to be communicated to the intended session initiation protocol proxy server.

17. The method of claim 16 further comprising storing the session initiation protocol signal in a data store.

18. The method of claim 16 further comprising:

processing a header of the session initiation protocol signal to determine a transaction identifier of the session initiation protocol signal;

determining whether the transaction identifier of the session initiation protocol signal matches the transaction identifier a transaction identifier of at least one session initiation protocol signal stored in the data store; and

allowing the plurality of packets to be communicated to the intended session initiation protocol proxy server if the transaction identifier matches the transaction identifier of at least one session initiation protocol signal stored in the data store, otherwise dropping the plurality of packets.

19. The method of claim 16 wherein the header comprises a uniform resource identifier, a branch parameter and a command sequence parameter, and the transaction identifier of the session initiation protocol signal is determined by calculating a 32-bit hash of the uniform resource identifier, the branch parameter and the command sequence parameter.

20. The method of claim 16 further comprising:

determining a number of session initiation protocol signals in the data store received over a period of time having a transaction identifier matching the transaction identifier of the intercepted signal

dropping the plurality of packets if the determined number of session initiation protocol signals exceeds a rate limit, otherwise allowing the plurality of packets to be communicated to the intended session initiation protocol proxy server.