Emulating shellcode attacks

• US 10,567,431 B2
• Filed: 05/17/2016
• Issued: 02/18/2020
• Est. Priority Date: 05/07/2014
• Status: Active Grant

• Current Assignee: SentinelOne Inc.
• Original Assignee: Attivo Networks, Inc.
• Inventors: Vissamsetty, Venu, Singh, Navtej, Kajekar, Sachin
• Primary Examiner(s): Najjar, Saleh
• Assistant Examiner(s): Mejia, Feliciano S
• Application Number:
  US15/157,082
• Publication Number:
  US 20160261631A1
• Time in Patent Office: 1,372 Days
• Field of Search: 726 22- 25
• CPC Class Codes: H04L 2463/142 Denial of service attacks against network infrastructure
• CPC Class Codes: H04L 2463/144 Detection or countermeasures against botnets
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/1408 by monitoring network traffic monitoring network traffic per se H04L43/00
• CPC Class Codes: H04L 63/1416 Event detection, e.g. attack signature detection
• CPC Class Codes: H04L 63/1441 Countermeasures against malicious traffic countermeasures against attacks on cryptographic mechanisms H04L9/002
• 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 63/1491 using deception as countermeasure, e.g. honeypots, honeynets, decoys or entrapment

Abstract

A system includes one or more “BotMagnet” modules that are exposed to infection by malicious code. The BotMagnets may include one or more virtual machines hosing operating systems in which malicious code may be installed and executed without exposing sensitive data or other parts of a network. In particular, outbound traffic may be transmitted to a Sinkhole module that implements a service requested by the outbound traffic and transmits responses to the malicious code executing within the BotMagnet. In the case of shellcode attacks, unsuccessful attacks may be emulated by selecting a corresponding emulator that will receive and execute instructions, as would a successful shellcode attack. Events occurring on the BotMagnet and Sinkhole are correlated and used to characterize the malicious code. The characterization may be transmitted to other computer systems in order to detect instances of the malicious code.

Claims

1. A method comprising:

receiving, by a target system from an intruder system, a shellcode including executable and operational instructions effective, when executed, to cause vulnerable software to receive and execute instructions using the shellcode, the vulnerable software including at least one of a service and an application, the target system not hosting the vulnerable software;

detecting, by the target system, failure of installation of the shellcode on the target system; and

in response to detecting failure of installation of the shellcode on the target system, performing (a) through (g), wherein (a) through (g) include

(a) identifying, by the target system, a type of the shellcode;

(b) selecting, by the target system, a shellcode emulator corresponding to the type of the shellcode, the target system not being vulnerable to the type of the shell code;

(c) at least one of (i) binding the shellcode emulator to a port indicated by the shellcode and (ii) connecting the shellcode emulator to the intruder system;

(d) receiving, by the target system, instructions from the intruder system directed to the shellcode, the shell code having failed to install on the target system;

(e) executing, by the target system, the instructions by the shellcode emulator effective to simulate successful installation of the shellcode;

(f) characterizing, by a detection system, behavior of the shellcode according to the instructions to generate a shellcode characterization; and

(g) transmitting, by the detection system, the characterization to a plurality of computer systems.

2. The method of claim 1, further comprising, wherein characterizing behavior of the shellcode according to the instructions comprises recording one or more of:

network connections invoked by the instructions;

file system activities invoked by the instructions;

process activities invoked by the instructions; and

system calls invoked by the instructions.

3. The method of claim 1, further comprising:

detecting, by the target system, outbound traffic from the shellcode emulator invoked by the instructions;

in response to detecting outbound traffic invoked by the instructions, transmitting, by the target system, the outbound traffic to a sinkhole module;

processing, by the sinkhole module, the outbound traffic and returning a response to the shellcode emulator.

4. The method of claim 1, further comprising:

detecting, by the target system, outbound traffic from the shellcode emulator invoked by the instructions;

identifying a service requested by the outbound traffic;

instantiating a sinkhole module and provisioning the sinkhole module with the service in response to detecting the outbound traffic and identifying the service; and

processing, by the sinkhole module, the outbound traffic and returning a response to the shellcode emulator.

5. The method of claim 1, further comprising binding an instance of the shellcode emulator to a port of the target system;

wherein receiving the instructions from the intruder system comprises receiving the instructions at the port.

6. The method of claim 1, further comprising:

transmitting access information for an instance of the shellcode emulator executing on the target system to the intruder system.

7. The method of claim 1, wherein identifying the type of the shellcode comprises evaluating a signature of data constituting the shellcode.

8. The method of claim 1, wherein identifying the type of the shellcode comprises evaluating assembler code of the shellcode.

9. The method of claim 1, wherein the target system executes a secure service operable to accept requests to create a secure connection to a remote system, authenticate a user on the remote system, and execute instructions from the user;

and

wherein the secure service performs all of determining blocking of installation of the shellcode on the target system, identifying a type of the shellcode, receiving instructions from the intruder system, and executing, by the target system, the instructions by the shellcode emulator.

10. The method of claim 1, wherein selecting the shellcode emulator corresponding to the type comprises retrieving a definition of the shellcode emulator from a database storing a plurality of shellcode definitions.

11. A system comprising one or more processors and one or more memory devices storing executable and operational code, the executable and operational code effective to cause the one or more processors to:

receive, from an intruder system, a shellcode including executable and operational instructions effective, when executed, to cause the target system to execute a shell for receiving and executing instructions on the target system;

determine failure of installation of the shellcode on the target system due to the target system not being vulnerable to the shellcode; and

in response to failure of installation of the shellcode on the target system performing (a) through (f), wherein (a) through (f) include

(a) identify a type of the shellcode;

(b) select a shellcode emulator corresponding to the type of the shellcode;

(c) receive instructions from the intruder system directed to the shellcode, the shellcode not installed on the system;

(d) execute the instructions by the shellcode emulator;

(e) characterize behavior of the shellcode according to the instructions to generate a shellcode characterization; and

(f) transmit the characterization to a plurality of computer systems.

12. The system of claim 11, wherein the executable and operational code are further effective to cause the one or more processors to characterize behavior of the shellcode according to the instructions by recording one or more of:

network connections invoked by the instructions;

file system activities invoked by the instructions;

process activities invoked by the instructions; and

system calls invoked by the instructions.

13. The system of claim 11, wherein the executable and operational code are further effective to cause the one or more processors to:

detect outbound traffic from the shellcode emulator invoked by the instructions;

in response to detecting outbound traffic invoked by the instructions, transmit the outbound traffic to a sinkhole module;

process the outbound traffic and returning a response to the shellcode emulator.

14. The system of claim 11, wherein the executable and operational code are further effective to cause the one or more processors to:

detect outbound traffic from the shellcode emulator invoked by the instructions;

identify a service requested by the outbound traffic;

instantiate a sinkhole module and provisioning the sinkhole module with the service in response to detecting the outbound traffic and identifying the service; and

process, by the sinkhole module, the outbound traffic and return a response to the shellcode emulator.

15. The system of claim 11, wherein the executable and operational code are further effective to:

cause the one or more processors to bind an instance of the shellcode emulator to a port of the target system;

receive the instructions from the intruder system by receiving the instructions at the port.

16. The system of claim 11, wherein the executable and operational code are further effective to cause the one or more processors to:

transmit access information for an instance of the shellcode emulator executing on the target system to the intruder system.

17. The system of claim 11, wherein the executable and operational code are further effective to cause the one or more processors to identify the type of the shellcode by evaluating a signature of data constituting the shellcode.

18. The system of claim 11, wherein the executable and operational code are further effective to cause the one or more processors to identify the type of the shellcode by evaluating assembler code of the shellcode.

19. The system of claim 11, wherein the executable and operational code are further effective to cause the one or more processors to execute a secure service operable to accept requests to create a secure connection to a remote system, authenticate a user on the remote system, and execute instructions from the user;

and

wherein the secure service includes executable and operational code effective to perform all of determining blocking of installation of the shellcode on the target system, identifying a type of the shellcode, receiving instructions from the intruder system, and executing, by the target system, the instructions by the shellcode emulator.

20. The system of claim 11, wherein the executable and operational code are further effective to cause the one or more processors to select the shellcode emulator corresponding to the type by retrieving a definition of the shellcode emulator from a database storing a plurality of shellcode definitions.