Detecting anomalous web proxy activity

• US 7,661,136 B1
• Filed: 12/13/2005
• Issued: 02/09/2010
• Est. Priority Date: 12/13/2005
• Status: Expired due to Fees

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Spielman, Chaim
• Primary Examiner(s): LAFORGIA, CHRISTIAN A
• Application Number:
  US11/301,541
• Time in Patent Office: 1,519 Days
• Field of Search: 726 22- 25
• US Class Current: 726/22
• CPC Class Codes: G06F 2221/2101 Auditing as a secondary aspect
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 63/0227 Filtering policies mail message filtering H04L51/212
• CPC Class Codes: H04L 63/1416 Event detection, e.g. attack signature detection
• CPC Class Codes: H04L 63/1425 Traffic logging, e.g. anomaly detection

Abstract

A method, system and apparatus for detecting anomalous web proxy activity by end-users are disclosed. The techniques include analyzing records from a web proxy log and determining whether the records contain anomalous end-user activity by inspecting a uniform resource locator and a connect instruction included therein. The techniques also include generating an alert in response to the analysis.

Claims

1. A method of detecting anomalous web proxy activity comprising:

extracting a plurality of records from a proxy log for a specified time period using a detection module implemented by a server;

filtering the plurality of records extracted from the proxy log by the detection module to exclude records that do not include identified information, the identified information being at least an Internet Protocol (IP) address at a beginning of a uniform resource locator (URL) field and a connect instruction;

determining, with the detection module, whether a first one of the records extracted from a web proxy log, and not excluded by the filtering, comprises suspicious web activity based on a number of distinct destination hosts to which a source connects; and

generating an alert in response to the determination by the detection module.

2. The method of claim 1, further comprising parsing the record by comparing a time entry of the record to a configurable time period.

3. The method of claim 1, wherein the connect instruction is a Hyper Text Transfer Protocol connect method.

4. The method of claim 1 comprising parsing the uniform resource locator field for the destination Internet Protocol address.

5. The method of claim 4 comprising calculating a sum of the distinct Internet Protocol addresses for a source internet protocol address included in the record.

6. The method of claim 5 comprising comparing the sum of distinct Internet Protocol addresses to a threshold number.

7. The method of claim 6 comprising generating the alert based on the comparison.

8. An article comprising a machine-readable medium storing machine-readable instructions that, when applied to a machine, cause the machine to:

extract a plurality of records from a proxy log for a specified time period;

filter the plurality of records extracted from the proxy log to exclude records that do not include identified information, the identified information being at least an Internet Protocol (IP) address at a beginning of a uniform resource locator (URL) field and a connect instruction;

determine whether a first one of the records extracted from a web proxy log, and not excluded by the filtering, comprises suspicious web activity based on a number of distinct destination hosts to which a source connects; and

generate an alert in response to the determination.

9. The article of claim 8 including instructions that, when applied to the machine, cause the machine to compare a time entry of the record to a configurable time period.

10. The article of claim 8 including instructions that, when applied to the machine, cause the machine to parse the numeric uniform resource locator field for the Internet Protocol address.

11. The article of claim 10 including instructions that, when applied to the machine, cause the machine to calculate a sum of the distinct Internet Protocol addresses for a source internet protocol address included in the record.

12. The article of claim 11 including instructions that, when applied to the machine, cause the machine to compare the sum of distinct Internet Protocol addresses to a threshold number.

13. The article of claim 12 including instructions that, when applied to the machine, cause the machine to generate the alert based on the comparison.

14. The article of claim 13 including instructions that, when applied to the machine, cause the machine to transmit the alert to a system administrator.

15. A system comprising a service delivery device coupled to a network, the service delivery device including a processor and memory storing instructions that, in response to receiving a request for access to a service, cause the processor to:

extract a plurality of records from a proxy log for a specified time period;

filter the plurality of records extracted from the proxy log to exclude records that do not include identified information, the identified information being at least an Internet Protocol (IP) address at a beginning of a uniform resource locator (URL) field and a connect instruction;

determine whether a first one of the records extracted from a web proxy log, and not excluded by the filtering, comprises suspicious web activity based on a number of distinct destination hosts to which a source connects; and

generate an alert in response to the determination.

16. The system of claim 15, wherein the memory stores instructions that, in response to receiving the request over the network, cause the processor to compare a time entry of the record to a configurable time period.

17. The system of claim 15, wherein the memory stores instructions that, in response to receiving the request over the network, cause the processor to parse the numeric uniform resource locator for the Internet Protocol address.

18. The system of claim 17, wherein the memory stores instructions that, in response to receiving the request over the network, cause the processor to calculate a sum of the distinct Internet Protocol addresses for a source internet protocol address included in the record.

19. The system of claim 18, wherein the memory stores instructions that, in response to receiving the request over the network, cause the processor to compare the sum of distinct Internet Protocol addresses to a threshold number.

20. The system of claim 19, wherein the memory stores instructions that, in response to receiving the request over the network, cause the processor to generate the alert based on the comparison.