System and method of protecting client computers

• US 10,223,530 B2
• Filed: 11/13/2013
• Issued: 03/05/2019
• Est. Priority Date: 11/13/2013
• Status: Active Grant

• Current Assignee: Proofpoint Incorporated
• Original Assignee: Proofpoint Incorporated
• Inventors: Tock, Theron D., Horn, Michael P.
• Primary Examiner(s): Sholeman, Abu S
• Application Number:
  US14/079,565
• Publication Number:
  US 20150135317A1
• Time in Patent Office: 1,938 Days
• Field of Search: 726 22- 25
• CPC Class Codes: G06F 21/56 Computer malware detection or handling, e.g. anti-virus arrangements
• CPC Class Codes: H04L 2463/144 Detection or countermeasures against botnets

Abstract

A threat response platform to act as a bridge between non-inline security programs and inline security programs. The threat response platform receives event reports, relating to client devices, from the non-inline security programs and creates incident reports for a user. The incident reports describe the event report and also additional data gathered by an active correlation system of the threat response platform. The active correlation system automatically gathers various types of data that are potentially useful to a user in determining whether the reported event is an incidence of malware operating on the client device or a false positive. The active correlation system places a temporary agent on the client device to identify indications of compromise.

Claims

1. A method of providing security for a plurality of client computers, the method comprising:

receiving, by a threat response computer, an event report identifying possible malware on a first client computer;

receiving, by the threat response computer, a first set of data from a detection program running on the first client computer, said data reflecting the state of the first client computer by including at least one of registry entries, files, mutexes, open connections, or processes running on the first client computer;

automatically analyzing the first set of data based on a set of known actual indications of compromise (IOCs) related to the possible malware, said actual IOCs containing data that identify changes to a computer that has been infected with malware comprising changed or added files, changed or added registry entries, mutexes, processes, or open connections;

receiving a second set of data from a second client computer;

updating the set of known actual IOCs with information that may be used to identify when malware has been executed on the first client computer, wherein updating the set of known actual IOCs comprises analyzing the second set of data and re-weighting the known actual IOCs found in both the first set of data and the second set of data;

automatically re-analyzing the first set of data based on the update;

performing at least one of presenting the re-analysis to a user; and

configuring a firewall in response to the re-analysis indicating that the first client has been infected with malware.

2. The method of claim 1, wherein updating the set of known actual IOCs comprises adding a new set of known actual IOCs to the set of known actual IOCs.

3. The method of claim 1, wherein re-weighting a known actual IOC comprises changing a correlation value of the known actual IOC, wherein the correlation value is used to calculate a probability that the first client computer is infected based on the known actual IOCs in the first set of data.

4. The method of claim 1, further comprising:

receiving a plurality of sets of data from a plurality of client computers, wherein updating the set of known actual IOCs comprises analyzing the plurality of sets of data and re-weighting known actual IOCs found in the plurality of sets of data received from the plurality of client computers.

5. The method of claim 1, wherein the automatic re-analysis is performed only when the analysis determines that a particular malware related to the known actual IOCs is not proven to be present on the client computer.

6. The method of claim 1, wherein the update is a first update and the re-analysis is a first re-analysis, the method further comprising:

repeatedly updating the set of known actual IOCs; and

repeatedly automatically re-analyzing the set of data.

7. A non-transitory machine readable medium storing a program which when executed by at least one processing unit provides security for a plurality of client computers, the program comprising sets of instructions for:

receiving an event report identifying a possible infection of a first client computer;

receiving a first set of data from a detection program running on the first client computer, said data reflecting the state of the first client computer by including at least one of registry entries, files, mutexes, open connections, or processes running on the first client computer;

automatically analyzing the first set of data based on a set of known actual indications of compromise (IOCs) where the actual IOCs are client computer behaviors comprising filenames of recently added or changed files, mutexes, recently changed or added registry keys, open connections, or processes;

receiving a second set of data from a second client computer;

updating the set of known actual IOCs, wherein updating the set of know actual IOCs comprises analyzing the second set of data and re-weighting the set of known actual IOCs found in both the first set of data and the second set of data;

automatically re-analyzing the first set of data based on the update to the set of known actual IOCs;

performing at least one of presenting the re-analysis to a user; and

configuring a firewall in response to the re-analysis indicating that the first client computer has been infected with malware.

8. The machine readable medium of claim 7, wherein updating the set of known actual IOCs comprises adding a new set of known actual IOCs to the set of known actual IOCs.

9. The machine readable medium of claim 7, wherein re-weighting a known actual IOC comprises changing a correlation value of the known actual IOC, wherein the correlation value is used to calculate a probability that a client computer is infected based on known actual IOCs found in a set of data of the client computer.

10. The machine readable medium of claim 9, wherein the re-weighting of the known actual IOC increases the correlation value when the second set of data is determined as indicating malware, wherein increasing the correlation value increases the calculated probability that the first client computer is infected.

11. The machine readable medium of claim 9, wherein the re-weighting of the known actual IOC decreases the correlation value when the second set of data is determined as not indicating malware, wherein decreasing the correlation value decreases the calculated probability that the first client computer is infected.

12. The machine readable medium of claim 7, wherein the program further comprises a set of instructions for receiving a plurality of sets of data from a plurality of client computers, wherein updating the set of known actual IOCs comprises analyzing the plurality of sets of data and re-weighting known actual IOCs found in the plurality of sets of data received from the plurality of client computers.

13. The machine readable medium of claim 7, wherein the update is a first update and the re-analysis is a first re-analysis, the program further comprising sets of instructions for:

repeatedly updating the set of known actual IOCs; and

repeatedly automatically re-analyzing the set of data.

14. A device comprising at least one processing unit and a memory storing a program which when executed by the processing unit provides security for a plurality of client computers, the program comprising sets of instructions for:

receiving, at the device, an event report identifying a possible infection of a first client computer;

receiving, at the device, a first set of data from the first client computer, said data reflecting the state of the first client computer by including at least one of registry entries, files, mutexes, or processes running on the first client computer;

automatically analyzing the first set of data based on a set of known actual indications of compromise (IOCs), said actual IOCs containing data that identify changes to a computer that has been infected with malware comprising changed or added files, changed or added registry entries, mutexes, open connections, or processes;

receiving, at the device, a second set of data from a second client computer;

updating the set of known actual IOCs with information that may be used to identify when malware has been executed on the client computer, wherein updating the set of know actual IOCs comprises analyzing the second set of data and re-weighting the set of known actual IOCs found in both the first set of data and the second set of data;

automatically re-analyzing the first set of data based on the update to the set of known actual IOCs;

performing at least one of presenting the re-analysis to a user; and

configuring a firewall in response to the re-analysis indicating that the first client computer has been infected with malware.

15. The device of claim 14, wherein the program further comprises sets of instructions for:

before re-analyzing the set of data, determining whether the set of data is obsolete; and

re-analyzing the set of data only when the set of data is not obsolete.

16. The device of claim 15, wherein the set of data is obsolete when it was received more than a threshold time before updating the set of known actual IOCs .

17. The device of claim 15, wherein the set of data is obsolete when the client computer has been re-imaged before updating the set of known actual IOCs.

18. The device of claim 14, wherein the event report is received from a threat detection program not running on the device.