Methods, systems, and computer readable media for efficient computer forensic analysis and data access control

Patent metadata

Field	Value
Publication number	US-9721089-B2
Application number	US-201214115094-A
Country	US
Kind code	B2
Filing date	May 7, 2012
Priority date	May 6, 2011
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

According to one aspect, the subject matter described herein includes a method for efficient computer forensic analysis and data access control. The method includes steps occurring from within a virtualization layer separate from a guest operating system. The steps include monitoring disk accesses by the guest operating system to a region of interest on a disk from which data is copied into memory. The steps also include tracking subsequent accesses to the memory resident data where the memory resident data is copied from its initial location to other memory locations or over a network. The steps further include linking operations made by the guest operating system associated with the disk accesses with operations made by the guest operating system associated with the memory accessed.

First claim

What is claimed is:

1. A method for efficient computer forensic analysis and data access control, the method comprising:
from within a virtualization layer of a first computing system separate from a guest operating system executing on the first computing system:
monitoring disk accesses by the guest operating system to a region of interest on a disk from which data is copied into memory;
tracking subsequent accesses to memory resident data where the memory resident data is copied from its initial location to other memory locations or over a network;
linking operations made by the guest operating system associated with the disk accesses with operations made by the guest operating system associated with the memory accesses, wherein the operations made by the guest operating system associated with the disk accesses include a file read operation and wherein linking the operations made by the guest operating system associated with the disk accesses with the operations associated with the memory accesses includes examining source and destination parameters associated with the file read operation to infer that the operations concern the same data; and
selectively blocking accesses by the guest operating system to memory or disk locations containing data of interest.

2. The method of claim 1 wherein the virtualization layer comprises a hypervisor layer.

3. The method of claim 1 wherein monitoring disk accesses includes maintaining a watch list of virtual machine disk blocks containing data of interest and determining whether a disk access corresponds to any of the virtual machine blocks on the watch list.

4. The method of claim 3 wherein tracking subsequent accesses to the memory resident data includes, in response to determining that the disk access corresponds to a virtual machine disk block on the watch list, triggering a memory monitoring module located within the virtualization layer to monitor a physical page of memory into which blocks of data from the disk access are paged.

5. The method of claim 1 comprising maintaining a watch list of file system objects corresponding to data of interest and determining whether a file system object operation corresponds to any of the file system objects on the watch list.

6. The method of claim 1 wherein tracking subsequent accesses to the memory resident data includes, in response to the memory resident data being copied from its initial location to another memory resident location, adding the new memory resident location to a watch list and monitoring subsequent accesses to the new memory resident location using the watch list.

7. The method of claim 1 comprising identifying a codepage signature of a process making the memory accesses and comparing the codepage signature to stored codepage signatures to identify the process.

8. The method of claim 7 comprising creating the codepage signature for the process by recognizing shared and kernel code pages associated with the process and utilizing the codepage signature to selectively extract codepages that identify the process.

9. The method of claim 1 comprising selectively blocking or dropping packets associated with a network connection without examining the packets' contents.

10. A system for efficient computer forensic analysis and data access control, the system comprising:
a virtualization layer of a first computing system separate from a guest operating system executing on the first computing system for virtualizing resources of the first computing system;
a storage monitoring module located within the virtualization layer and for monitoring disk accesses by the guest operating system to a region of interest on a disk from which data is copied into memory;
a memory monitoring module located within the virtualization layer for tracking subsequent accesses to memory resident data where the memory resident data is copied from its initial location to other memory locations or over a network;
a system call monitoring module for linking operations made by the guest operating system associated with the disk accesses with operations made by the guest operating system associated with the memory accesses, wherein the operations made by the quest operating system associated with the disk accesses include a file read operation and wherein linking the operations made by the guest operating system associated with the disk accesses with the operations associated with the memory accesses includes examining source and destination parameters associated with the file read operation to infer that the operations concern the same data; and
an enforcement module for selectively blocking accesses by the guest operating system to memory or disk locations containing data of interest, wherein each of the storage monitoring module, the memory monitoring module, the system call monitoring module, and the enforcement module is implemented using at least one hardware processor.

11. The system of claim 10 wherein the virtualization layer comprises a hypervisor layer.

12. The system of claim 10 wherein the storage monitoring module is configured to maintain a watch list of virtual machine disk blocks containing data of interest and determine whether a disk access corresponds to any of the virtual machine blocks on the watch list.

13. The system of claim 12 wherein the storage monitoring module is configured to, in response to determining that the disk access corresponds to a virtual machine disk block on the watch list, trigger the memory monitoring module to monitor a physical page of memory into which blocks of data from the disk access are paged.

14. The system of claim 10 wherein the storage monitoring module is configured to maintain a watch list of file system objects corresponding to data of interest and determine whether a file system object operation corresponds to any of the file system objects on the watch list.

15. The system of claim 10 wherein the memory monitoring module is configured to, in response to the memory resident data being copied from its initial location to another memory resident location, add the new memory resident location to a watch list and monitor subsequent accesses to the new memory resident location using the watch list.

16. The system of claim 10 wherein the memory monitoring module is configured to identify a codepage signature of a process making the memory accesses and to compare the codepage signature to stored codepage signatures to identify the process.

17. The system of claim 16 wherein the memory monitoring module is configured to create the codepage signature for the process by recognizing shared and kernel code pages associated with the process and utilize the codepage signature to selectively extract codepages that identify the process.

18. The system of claim 10 comprising a network monitoring module configured to, in response to a trigger from either the memory monitoring module or the system call monitoring module, selectively block or drop packets associated with a network connection.

19. A non-transitory computer readable medium having stored thereon executable instructions that when executed by a processor of a computer control the computer to perform steps comprising:
from within a virtualization layer of a first computing system separate from a guest operating system executing on the first computing system:
monitoring disk accesses by the guest operating system to a region of interest on a disk from which data is copied into memory;
tracking subsequent accesses to the memory resident data where the memory res

Assignees

• Krishnan Srinivas
• Monrose Fabian
• Snow Kevin
• Univ North Carolina Chapel Hill

Inventors

• Krishnan Srinivas
• Monrose Fabian
• Snow Kevin

Classifications

• G06F21/53 Primary

  by executing in a restricted environment, e.g. sandbox or secure virtual machine · CPC title

• G06F21/50 Primary

  Monitoring users, programs or devices to maintain the integrity of platforms, e.g. of processors, firmware or operating systems · CPC title