MALICIOUS CODE INFECTION CAUSE-AND-EFFECT ANALYSIS

• US 20120144490A1
• Filed: 02/08/2012
• Published: 06/07/2012
• Est. Priority Date: 11/30/2004
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Hartrell, Gregory D., Steeves, David J., Hudis, Efim
• Granted Patent: US 8,955,134 B2
• Time in Patent Office: Days
• US Class Current: 726/24
• CPC Class Codes: G06F 21/552 involving long-term monitoring or reporting
• CPC Class Codes: G06F 21/565 by checking file integrity
• CPC Class Codes: G06F 2221/034 Test or assess a computer or a system
• 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 malware analysis system for automating cause and effect analysis of malware infections is provided. The malware analysis system monitors and records computer system activities. Upon being informed of a suspected malware infection, the malware analysis system creates a time-bounded snapshot of the monitored activities that were conducted within a time frame prior to the notification of the suspected malware infection. The malware analysis system may also create a time-bounded snapshot of the monitored activities that are conducted within a time frame subsequent to the notification of the suspected malware infection. The malware analysis system provides the created snapshot or snapshots for further analysis.

Claims

1. A computer-readable storage device containing computer-executable instructions for controlling a computing device to analyze a malware infection by a method comprising:

receiving pre-infection snapshots from a plurality of machines suspected of being infected with malware, the pre-infection snapshots identifying monitored activities that were conducted at machines suspected of being infected with malware prior to the machine being suspected of being infected with malware;

comparing the monitored activities of the pre-infection snapshots to identify monitored activities that are common across multiple pre-infection snapshots; and

tagging as being suspicious at least some monitored activities that are common across multiple pre-infection snapshots.

2. The computer-readable storage device of claim 1 including prior to comparing the monitored activities, normalizing the monitored activities.

3. The computer-readable storage device of claim 2 wherein the normalizing includes associating categories with the monitored activities.

4. The computer-readable storage device of claim 3 wherein a first monitored activity of a first machine and a second monitored activity of a second machine are common when associated with the same category.

5. The computer-readable storage device of claim 2 including mapping the normalized activities to a malware state of a malware state model.

6. The computer-readable storage device of claim 1 including:

receiving post-infection snapshots from a plurality of machines suspected of being infected with malware, each of the post-infection snapshots identifying monitored activities that were conducted at each machine suspected of being infected with malware subsequent to the machine being suspected of being infected with malware; and

comparing the monitored activities of the post-infection snapshot to identify monitored activities that are common across multiple post-infection snapshots.

7. The computer-readable storage device of claim 6 including tagging as possibly being caused by the infection the monitored activities that are common across multiple post-infection snapshots.

8. A computer-readable storage device containing computer-executable instructions for controlling a computing device to analyze a malware infection by a method comprising:

receiving snapshots of machines suspected of being infected with malware, the snapshots identifying monitored activities of machines suspected of being infected with malware during a time frame associated with the machines being suspected of being infected with malware; and

comparing the monitored activities of the snapshots to identify monitored activities that may be related to a cause of the malware infection.

9. The computer-readable storage device of claim 8 wherein the snapshots are pre-infection snapshots.

10. The computer-readable storage device of claim 8 wherein the comparing identifies monitored activities that are common across multiple snapshots.

11. The computer-readable storage device of claim 10 including prior to comparing the monitored activities, normalizing the monitored activities.

12. The computer-readable storage device of claim 11 wherein the normalizing includes associating categories with the monitored activities.

13. The computer-readable storage device of claim 8 including automatically re-configuring security policies to prevent future malware infections.

14. The computer-readable storage device of claim 8 including after identifying monitored activities that may be related to a cause of the malware infection, providing a recommendation for responding to the malware infection.

15. A computing device for analyzing a malware infection comprising:

a data store storing pre-infection snapshots of a plurality of machines suspected of being infected with malware, the pre-infection snapshots identifying monitored activities that were performed at machines suspected of being infected with malware prior to the machines being suspected of being infected with malware;

a memory storing computer-executable instructions of;

a component that identifies monitored activities that are common across multiple pre-infection snapshots; and

a component that indicates the monitored activities that are common across multiple pre-infection snapshots may be related to the cause of the infection; and

a processor that executes the computer-executable instructions stored in the memory.

16. The computing device of claim 15 including a component that, prior to comparing the monitored activities, normalizes the monitored activities.

17. The computing device of claim 16 wherein the component that normalizes associates categories with the monitored activities.

18. The computing device of claim 17 wherein a first normalized activity of a first machine and a second normalized activity of a second machine are common when associated with the same category.

19. The computing device of claim 16 wherein the computer-executable instructions include an expert system that, after monitored activities are identified, provides a recommendation for responding to the malware infection based on the identified monitored activities.

20. The computing device of claim 15 wherein the data store stores post-infection snapshots of a plurality of machines suspected of being infected with malware, each of the post-infection snapshots identifying monitored activities that were performed at each machine suspected of being infected with malware within a time frame subsequent to the machine being suspected of being infected with malware and wherein the computer-executable instructions stored in the memory include:

a component that identifies monitored activities that are common across multiple post-infection snapshots; and

a component that indicates monitored activities that are common across multiple post-infection snapshots may be caused by the malware infection.