SELECTIVE AUTHORIZATION OF THE LOADING OF DEPENDENT CODE MODULES BY RUNNING PROCESSES

• US 20110167261A1
• Filed: 03/11/2011
• Published: 07/07/2011
• Est. Priority Date: 12/03/2004
• Status: Active Grant

• Current Assignee: Fortinet Inc.
• Original Assignee: Fortinet Inc.
• Inventors: Harper, Edwin L., Godwin, Kurt E., Rozga, Anthony A., Fanton, Andrew F., Gandee, John J., Lutton, William H.
• Granted Patent: US 8,151,109 B2
• Time in Patent Office: Days
• US Class Current: 713/165
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/44 Program or device authentication
• CPC Class Codes: G06F 21/51 at application loading time, e.g. accepting, rejecting, starting or inhibiting executable software based on integrity or source reliability
• CPC Class Codes: G06F 21/52 during program execution, e.g. stack integrity ; Preventing unwanted data erasure; Buffer overflow
• CPC Class Codes: G06F 21/53 by executing in a restricted environment, e.g. sandbox or secure virtual machine
• CPC Class Codes: G06F 21/602 Providing cryptographic facilities or services
• CPC Class Codes: G06F 2221/033 Test or assess software
• CPC Class Codes: G06F 2221/2141 Access rights, e.g. capability lists, access control lists, access tables, access matrices
• CPC Class Codes: G06F 9/445 Program loading or initiating bootstrapping G06F9/4401; security arrangements for program loading or initiating G06F21/57
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/0884 by delegation of authentication, e.g. a proxy authenticates an entity to be authenticated on behalf of this entity vis-à-vis an authentication entity
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 63/145 the attack involving the propagation of malware through the network, e.g. viruses, trojans or worms
• CPC Class Codes: H04L 9/0643 Hash functions, e.g. MD5, SHA, HMAC or f9 MAC
• CPC Class Codes: H04L 9/32 including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials
• CPC Class Codes: H04L 9/3239 involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure

Abstract

Systems and methods for selective authorization of dependent code modules are provided. According to one embodiment, file system or operating system activity relating to a first code module is initiated by a running process associated with a second code module. The file system or operating system activity is intercepted by a kernel mode driver of a computer system. The kernel mode driver selectively authorizes loading of the first code module by the running process based at least in part on one or more attributes of the second code module.

Claims

1. A method comprising:

intercepting, by a kernel mode driver of a computer system, file system or operating system activity relating to a first code module initiated by a running process associated with a second code module;

selectively authorizing, by the kernel mode driver, loading of the first code module by the running process based at least in part on one or more attributes of the second code module; and

wherein the kernel mode driver is implemented in one or more processors and one or more computer-readable storage media associated with the computer system, the one or more computer-readable storage media having instructions tangibly embodied therein representing the kernel mode driver that are executable by the one or more processors.

2. The method of claim 1, wherein said selectively authorizing comprises determining whether the second code module comprises a script interpreter.

3. The method of claim 2, further comprising, if said determining whether the second code module comprises a script interpreter results in an affirmative determination, then authenticating a cryptographic hash value of the first code module with reference to a multi-level whitelist, the multi-level whitelist comprising (i) a global whitelist database remote from the computer system and maintained by a trusted service provider, the global whitelist database containing cryptographic hash values of approved code modules, which are known not to contain viruses or malicious code and (ii) a local whitelist database containing cryptographic hash values of at least a subset of the approved code modules.

4. The method of claim 3, further comprising allowing the running process to read the first code module if the cryptographic hash value matches one of the cryptographic hash values of approved code modules within the multi-level whitelist.

5. The method of claim 1, wherein the first code module comprises a non-executable code module.

6. The method of claim 5, wherein the first code module comprises a script file.

7. The method of claim 5, wherein the first code module comprises a Java applet.

8. The method of claim 5, wherein the first code module comprises a visual basic script.

9. The method of claim 5, wherein the first code module comprises a JavaScript.

10. The method of claim 1, wherein the cryptographic hash value is computed using Message Digest #5 (MD-5).

11. The method of claim 1, wherein the cryptographic hash value is computed using a Secure Hash Algorithm (SHA).

12. The method of claim 11, wherein the cryptographic hash value is computed using SHA-1.

13. The method of claim 11, wherein the cryptographic hash value is computed using SHA-256.

14. The method of claim 1, wherein said intercepting file system or operating system activity relating to a first code module comprises monitoring operating system process creation or module load activity.

15. The method of claim 14, wherein the kernel mode driver is configured for operation within a Microsoft Windows operating system.

16. The method of claim 15, wherein said intercepting file system or operating system activity relating to a first code module comprises an operating system module load activity monitor intercepting module load activity by running processes within the computer system by hooking to a Windows CreateSection API call and temporarily turning control over to the kernel mode driver.

17. The method of claim 16, wherein the first code module comprises an executable code module.

18. The method of claim 17, wherein the first code module comprises a dynamically-linked library file.

19. A code execution authorization system comprising:

a kernel mode driver of a computer system implemented in one or more computer processors of the computer system and one or more computer-readable storage media associated with the computer system, the one or more computer-readable storage media having instructions tangibly embodied therein representing the kernel mode driver that are executable by the one or more computer processors, the kernel mode driver operable to perform a method of authenticating dependent code modules requested to be loaded by processes running on the computer system comprising;

intercepting file system or operating system activity relating to a first code module initiated by a running process associated with a second code module; and

selectively authorizing loading of the first code module by the running process based at least in part on one or more attributes of the second code module.

20. The code execution authorization system of claim 19, wherein said selectively authorizing comprises determining whether the second code module comprises a script interpreter.

21. The code execution authorization system of claim 20, further comprising, if said determining whether the second code module comprises a script interpreter results in an affirmative determination, then authenticating a cryptographic hash value of the first code module with reference to a multi-level whitelist, the multi-level whitelist comprising (i) a global whitelist database remote from the computer system and maintained by a trusted service provider, the global whitelist database containing cryptographic hash values of approved code modules, which are known not to contain viruses or malicious code and (ii) a local whitelist database containing cryptographic hash values of at least a subset of the approved code modules.

22. The code execution authorization system of claim 21, further comprising allowing the running process to read the first code module if the cryptographic hash value matches one of the cryptographic hash values of approved code modules within the multi-level whitelist.

23. The code execution authorization system of claim 19, wherein the first code module comprises a non-executable code module.

24. The code execution authorization system of claim 19, wherein the cryptographic hash value is computed using Message Digest #5 (MD-5) or a Secure Hash Algorithm (SHA).

25. The code execution authorization system of claim 19, wherein the kernel mode driver is configured for operation within a Microsoft Windows operating system.

26. The code execution authorization system of claim 25, wherein said intercepting file system or operating system activity relating to a first code module comprises an operating system module load activity monitor intercepting module load activity by running processes within the computer system by hooking to a Windows CreateSection API call and temporarily turning control over to the kernel mode driver.

27. The code execution authorization system of claim 26, wherein the first code module comprises an executable code module.

28. The code execution authorization system of claim 27, wherein the first code module comprises a dynamically-linked library file.

29. A non-transitory program storage device readable by a computer system, tangibly embodying a program of instructions executable by one or more computer processors of the computer system to perform method steps for authenticating dependent code modules requested to be loaded by processes running on the computer system comprising:

intercepting, by a kernel mode drive, file system or operating system activity relating to a first code module initiated by a running process associated with a second code module; and

selectively authorizing, by the kernel mode drive, loading of the first code module by the running process based at least in part on one or more attributes of the second code module.

30. The non-transitory program storage device of claim 29, wherein said selectively authorizing comprises determining whether the second code module comprises a script interpreter.

31. The non-transitory program storage device of claim 30, further comprising, if said determining whether the second code module comprises a script interpreter results in an affirmative determination, then authenticating a cryptographic hash value of the first code module with reference to a multi-level whitelist, the multi-level whitelist comprising (i) a global whitelist database remote from the computer system and maintained by a trusted service provider, the global whitelist database containing cryptographic hash values of approved code modules, which are known not to contain viruses or malicious code and (ii) a local whitelist database containing cryptographic hash values of at least a subset of the approved code modules.

32. The non-transitory program storage device of claim 31, further comprising allowing the running process to read the first code module if the cryptographic hash value matches one of the cryptographic hash values of approved code modules within the multi-level whitelist.

33. The non-transitory program storage device of claim 29, wherein the first code module comprises a non-executable code module.

34. The non-transitory program storage device of claim 29, wherein the cryptographic hash value is computed using Message Digest #5 (MD-5) or a Secure Hash Algorithm (SHA).

35. The non-transitory program storage device of claim 29, wherein the kernel mode driver is configured for operation within a Microsoft Windows operating system.

36. The non-transitory program storage device of claim 35, wherein said intercepting file system or operating system activity relating to a first code module comprises an operating system module load activity monitor intercepting module load activity by running processes within the computer system by hooking to a Windows CreateSection API call and temporarily turning control over to the kernel mode driver.

37. The non-transitory program storage device of claim 36, wherein the first code module comprises an executable code module.

38. The non-transitory program storage device of claim 37, wherein the first code module comprises a dynamically-linked library file.