System and method for scanning memory for pestware offset signatures

• US 7,591,016 B2
• Filed: 04/14/2005
• Issued: 09/15/2009
• Est. Priority Date: 04/14/2005
• Status: Active Grant

• Current Assignee: Carbonite LLC (Open Text Corporation)
• Original Assignee: Webroot Software Incorporated (Open Text Corporation)
• Inventors: Horne, Jefferson Delk
• Primary Examiner(s): Vu; Kimyen
• Assistant Examiner(s): PATEL, NIRAV B
• Application Number:
  US11/105,977
• Publication Number:
  US 20060236396A1
• Time in Patent Office: 1,615 Days
• Field of Search: 726 22- 25, 713164-167, 713/188, 714/100, 714/5, 714/25, 714/29, 714/39, 714/47, 717124-135, 711/200
• US Class Current: 726/22
• CPC Class Codes: G06F 21/56 Computer malware detection or handling, e.g. anti-virus arrangements
• CPC Class Codes: G06F 21/566 Dynamic detection, i.e. detection performed at run-time, e.g. emulation, suspicious activities

Abstract

Systems and methods for managing pestware processes on a protected computer are described. In one implementation, a reference point in the executable memory that is associated with a process running in the executable memory is located. A first and second sets of information from corresponding first and second portions of the executable memory are then retrieved. The first and second portions of the executable memory are separated by a defined offset, and each of the first and second portions of the executable memory are offset from the reference point. The process is identifiable as a particular type of pestware when the first and second sets of information each include information previously found to be separated by the defined offset in other processes that are of the particular type of pestware. In some variations, the reference point is a starting address and/or an API implementation in the process.

Claims

1. A method for scanning executable memory of a protected computer for pestware comprising:

identifying at least one reference point in the executable memory of the protected computer, wherein the at least one reference point is associated with a process being executed by the protected computer via the executable memory of the protected computer, wherein the process is potentially a predetermined type of pestware;

selecting a first offset and a second offset based on the predetermined type of pestware;

accessing the memory at the first offset from the at least one reference point so as to identify a first set of information in the executable memory that begins at the first offset from the at least one reference point;

accessing the memory at the second offset from the at least one reference point so as to identify a second set of information in the executable memory that begins at the second offset from the at least one reference point; and

wherein the first and second sets of information are separated in the executable memory by information not included in the first and second sets of information wherein the second set of information is spawned from the first set of information upon execution of the first set of information in the executable memory, and wherein the process is identifiable as the predetermined type of pestware when the first and second sets of information each include information specific to the predetermined type of pestware.

2. The method of claim 1, wherein the identifying includes identifying a start address as the at least one reference point.

3. The method of claim 1, wherein the identifying includes identifying a particular API implementation as the at least one reference point.

4. The method of claim 1, wherein accessing the memory at the first and second offsets includes accessing executable op code at the first and second offsets so as to identify executable op code in the first and second sets of information.

5. A method for scanning executable memory of a protected system for pestware comprising:

locating a reference point in the executable memory that is associated with a process being executed by a computer via the executable memory;

retrieving a first set of information from a first portion of the executable memory and a second set of information from a second portion of the executable memory, wherein the first and second portions of the executable memory are separated by a defined offset based on a predetermined type of pestware, and wherein each of the first and second portions of the executable memory are offset from the reference point;

identifying the process as the predetermined type of pestware when the first and second sets of information each include information previously found to be separated by the defined offset in other processes that are specific to the predetermined type of pestware wherein the second set of information is spawned from the first set of information upon execution of the first set of information in the executable memory; and

scanning a file of a hard drive associated with the process to obtain information about the file, wherein the defined offset varies based upon the information about the file.

6. The method of claim 5, wherein the locating the reference point includes locating a starting address of the process.

7. The method of claim 5, wherein the locating the reference point includes locating an API implementation in the process.

8. The method of claim 5, wherein the retrieving includes retrieving op code from the first and second portions of the executable memory.

9. A system for managing pestware comprising:

a protected computer;

a pestware removal module configured to remove pestware on the protected computer, the protected computer including at least one file storage device and an executable memory; and

a pestware detection module configured to;

locate a reference point in the executable memory that is associated with a process being executed by the protected computer via the executable memory,

retrieve a first set of information from a first portion of the executable memory and a second set of information from a second portion of the executable memory, wherein the first and second portions of the executable memory are separated by a defined offset based on a predetermined type of pestware, and wherein each of the first and second portions of the executable memory are offset from the reference point,

identify the process as the predetermined type of pestware when the first and second sets of information each include information previously found to be separated by the defined offset in other processes that are specific to the predetermined type of pestware, wherein the second set of information is spawned from the first set of information upon execution of the first set of information in the executable memory; and

scan a file of a hard drive associated with the process to obtain information about the file, and wherein the defined offset varies based upon the information about the file.

10. The system of claim 9, wherein the pestware detection module is configured to locate a starting address as the reference point.

11. The system of claim 9, wherein the pestware detection module is configured to locate an API implementation as the reference point.

12. The system of claim 9, wherein the pestware detection module is configured to retrieve op code from the first and second portions of the executable memory.

13. A computer readable storage medium storing instructions for scanning executable memory on a protected computer for pestware, the instructions including instructions for:

locating a reference point in the executable memory that is associated with a process being executed by the protected computer via the executable memory;

retrieving a first set of information from a first portion of the executable memory and a second set of information from a second portion of the executable memory, wherein the first and second portions of the executable memory are separated by a defined offset based on a predetermined type of pestware, and wherein each of the first and second portions of the executable memory are offset from the reference point;

identifying the process as the predetermined type of pestware when the first and second sets of information each include information previously found to be separated by the defined offset in other processes that are specific to the predetermined type of pestware wherein the second set of information is spawned from the first set of information upon execution of the first set of information in the executable memory; and

scanning a file of a hard drive associated with the process to obtain information about the file, wherein the defined offset varies based upon the information about the file.

14. The computer readable medium of claim 13, wherein the instructions for locating the reference point include instructions for locating a starting address of the process.

15. The computer readable medium of claim 13, wherein the instructions for locating the reference point include instructions for locating an API implementation in the process.

16. The computer readable medium of claim 13, wherein the instructions for retrieving include instructions for retrieving op code from the first and second portions of the executable memory.