Identifying a denial-of-service attack in a cloud-based proxy service

• US 9,628,509 B2
• Filed: 12/17/2013
• Issued: 04/18/2017
• Est. Priority Date: 08/07/2012
• Status: Active Grant

• Current Assignee: CloudFlare Incorporated
• Original Assignee: CloudFlare Incorporated
• Inventors: Rodery, Jr., Terry Paul, Holloway, Lee Hahn, Rao, Srikanth N., Prince, Matthew Browning, Tourne, Matthieu Philippe Franois, Pye, Ian Gerald, Bejjani, Ray Raymond
• Primary Examiner(s): Pham, Luu
• Assistant Examiner(s): Baum, Ronald
• Application Number:
  US14/109,815
• Publication Number:
  US 20140109225A1
• Time in Patent Office: 1,218 Days
• Field of Search: 726 23
• CPC Class Codes: G06F 21/552 involving long-term monitoring or reporting
• CPC Class Codes: G06F 21/577 Assessing vulnerabilities and evaluating computer system security
• CPC Class Codes: H04L 63/0281 Proxies
• CPC Class Codes: H04L 63/1408 by monitoring network traffic monitoring network traffic per se H04L43/00
• 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
• CPC Class Codes: H04L 63/1433 Vulnerability analysis
• CPC Class Codes: H04L 63/1458 Denial of Service
• CPC Class Codes: H04L 63/1466 Active attacks involving interception, injection, modification, spoofing of data unit addresses, e.g. hijacking, packet injection or TCP sequence number attacks
• CPC Class Codes: H04L 63/20 for managing network security; network security policies in general filtering policies H04L63/0227

Abstract

A cloud-based proxy service identifies a denial-of-service (DoS) attack including determining that there is a potential DoS attack being directed to an IP address of the cloud-based proxy service; and responsive to determining that there are a plurality of domains that resolve to that IP address, identifying the one of the plurality of domains that is the target of the DoS attack. The domain that is under attack is identified by scattering the plurality of domains to resolve to different IP addresses, where a result of the scattering is that each of those domains resolves to a different IP address, and identifying one of those plurality of domains as the target of the DoS attack by determining that there is an abnormally high amount of traffic being directed to the IP address in which that domain resolves.

Claims

1. A method in a cloud-based proxy service for identifying a target of a denial-of-service (DoS) attack, the method comprising:

determining that there is traffic indicative of the DoS attack directed to an IP address of the cloud-based proxy service;

responsive to determining that there are a plurality of domains that resolve to that same IP address, identifying the one of the plurality of domains that is the target of the DoS attack, wherein the step of identifying includes performing the following;

causing each of the plurality of domains to resolve to a respectively different IP address,

determining that the traffic indicative of the DoS attack is directed to a single one of the different IP addresses, and

identifying the target of the DoS attack as the one of the plurality of domains that resolves to the single one of the different IP addresses in which the traffic indicative of the DoS attack is directed; and

after identifying the target of the DoS attack, isolating the target of the DoS attack to a set of one or more data centers, wherein a set of one or more other domains that are not the target of the DoS attack initially belong to the set of data centers; and

moving that set of other domains to a different set of one or more data centers after identifying the target of the DoS attack.

2. The method of claim 1, wherein the step of causing each of the plurality of domains to resolve to a respectively different IP address includes causing one or more Domain Name System (DNS) records for each of the plurality of domains to be modified.

3. The method of claim 1, wherein the step of determining that traffic indicative of the DoS attack is being directed to the IP address includes determining that there is an abnormally high amount of traffic being directed to the IP address.

4. The method of claim 1, further comprising:

after identifying the target of the DoS attack, grouping at least some of those other ones of the plurality of domains to resolve to a same IP address of the cloud-based proxy service, wherein the step of grouping includes causing one or more Domain Name System (DNS) records for those domains to resolve to that same IP address.

5. The method of claim 1, further comprising:

after identifying the target of the DoS attack, performing one or more mitigation actions for the target of the DoS attack, including one or more of the following;

rate limiting traffic destined to the target of the DoS attack;

null routing the IP address in which the target of the DoS attack resolves;

installing filtering rules in network equipment of the cloud-based proxy service;

causing traffic destined to the target of the DoS attack to be directed to a dedicated DoS device of the cloud-based proxy service; and

presenting one or more challenges to visitors attempting to connect to the target of the DoS attack.

6. The method of claim 1, wherein the traffic indicative of the DoS attack directed to the IP address of the cloud-based proxy service is received as a result of the plurality of domains resolving to the IP address.

7. A non-transitory computer-readable storage medium that provides instructions that, when executed by a processor of a proxy server, will cause said processor to perform operations comprising:

determining that there is traffic indicative of a DoS attack directed to an IP address;

responsive to determining that there are a plurality of domains that resolve to that same IP address, identifying the one of the plurality of domains that is a target of the DoS attack, wherein the step of identifying includes performing the following;

causing each of the plurality of domains to resolve to a respectively different IP address,

determining that the traffic indicative of the DoS attack is directed to a single one of the different IP addresses, and

identifying the target of the DoS attack as the one of the plurality of domains that resolves to the single one of the different IP addresses in which the traffic indicative of the DoS attack is directed; and

after identifying the target of the DoS attack, isolating the target of the DoS attack to a set of one or more data centers, wherein a set of one or more other domains that are not the target of the DoS attack initially belong to the set of data centers; and

moving that set of other domains to a different set of one or more data centers after identifying the target of the DoS attack.

8. The non-transitory computer-readable storage medium of claim 7, wherein the step of causing each of the plurality of domains to resolve to a respectively different IP address includes causing one or more Domain Name System (DNS) records for each of the plurality of domains to be modified.

9. The non-transitory computer-readable storage medium of claim 7, wherein the step of determining that traffic indicative of the DoS attack is being directed to the IP address includes determining that there is an abnormally high amount of traffic being directed to the IP address.

10. The non-transitory computer-readable storage medium of claim 7, further comprising instructions that, when executed by the processor, cause said processor to perform the following operation:

after identifying the target of the DoS attack, grouping at least some of those other ones of the plurality of domains to resolve to a same IP address, wherein the step of grouping includes the proxy server causing one or more Domain Name System (DNS) records for those domains to resolve to that same IP address.

11. The non-transitory computer-readable storage medium of claim 7, further comprising instructions that, when executed by the processor, cause said processor to perform the following operation:

after identifying the target of the DoS attack, performing one or more mitigation actions for the target of the DoS attack, including one or more of the following;

rate limiting traffic destined to the target of the DoS attack;

null routing the IP address in which the target of the DoS attack resolves;

broadcasting filtering rules to network equipment downstream from the proxy server;

causing traffic destined to the target of the DoS attack to be directed to a dedicated DoS device; and

presenting one or more challenges to visitors attempting to connect to the target of the DoS attack.

12. The non-transitory computer-readable storage medium of claim 7, wherein the traffic indicative of a DoS attack directed to an IP address is received as a result of the plurality of domains resolving to the IP address.

13. An apparatus to identify a target of a denial-of-service (DoS) attack in a cloud-based proxy service, comprising:

a cloud-based proxy service node that includes a processor and a non-transitory machine-readable medium, the cloud-based proxy service node embodied in a single device or multiple devices and configured to perform the following;

determine that there is traffic indicative of the DoS attack directed to an IP address of the cloud-based proxy service;

responsive to a determination that there are a plurality of domains that resolve to that same IP address, identify the one of the plurality of domains that is the target of the DoS attack by performing the following;

cause each of the plurality of domains to resolve to a respectively different IP address,

determine that the traffic indicative of the DoS attack is directed to a single one of the different IP addresses, and

identify the target of the DoS attack as the one of the plurality of domains that resolves to the single one of the different IP addresses in which the traffic indicative of the DoS attack is directed; and

after identifying the target of the DoS attack, isolate the target of the DoS attack to a set of one or more data centers, wherein a set of one or more other domains that are not the target of the DoS attack initially belong to the set of data centers; and

move that set of other domains to a different set of one or more data centers after identifying the target of the DoS attack.

14. The apparatus of claim 13, wherein the cloud-based proxy service node is configured to cause each of the plurality of domains to resolve to a respectively different IP address by causing one or more Domain Name System (DNS) records for each of the plurality of domains to be modified.

15. The apparatus of claim 13, wherein the cloud-based proxy service node is configured to determine that traffic indicative of the DoS attack is being directed to the IP address includes determining that there is an abnormally high amount of traffic being directed to the IP address.

16. The apparatus of claim 13, further comprising:

after identifying the target of the DoS attack, the cloud-based proxy service node is configured to group at least some of those other ones of the plurality of domains to resolve to a same IP address of the cloud-based proxy service, wherein the cloud-based proxy service node is configured to group the at least some of those other ones of the plurality of domains by causing one or more Domain Name System (DNS) records for those domains to resolve to that same IP address.

17. The apparatus of claim 13, further comprising:

after identifying the target of the DoS attack, the cloud-based proxy service node is configured to perform one or more mitigation actions for the target of the DoS attack, including one or more of the following;

rate limiting traffic destined to the target of the DoS attack;

null routing the IP address in which the target of the DoS attack resolves;

install filtering rules in network equipment of the cloud-based proxy service;

cause traffic destined to the target of the DoS attack to be directed to a dedicated DoS device of the cloud-based proxy service; and

present one or more challenges to visitors attempting to connect to the target of the DoS attack.

18. The apparatus of claim 13, wherein the traffic indicative of the DoS attack directed to an IP address of the cloud-based proxy service is received as a result of the plurality of domains resolving to the IP address.