Method and system for protecting against unknown malicious activities by detecting a heap spray attack on an electronic device
View Patent ↗A method and system for protecting against unknown malicious activities by detecting a heap spray attack on a electronic device are disclosed. A script is received at an electronic device from a remote device via a network and a loop operation is detected in the script that contains a write operation operable to write data to a memory of the electronic device. The amount of the data operable to be written to the memory by the write operation is determined and the data is prevented from being written to the memory if the amount of the data is greater than or equal to a threshold.
1. A method for detecting a heap spray attack, comprising:
receiving a script at an electronic device from a remote device via a network;
detecting a loop operation in the script that contains a write operation operable to write data to a memory of the electronic device;
determining an amount of the data operable to be written to the memory by the write operation;
based at least on a determination that the data is greater than or equal to a threshold, detecting a potential heap spray attack and preventing the data from being written to the memory; and
based at least on a determination that the data is less than the threshold, allowing the script to be executed.
2. The method of claim 1 , wherein:
the amount of data comprises a size of the data based on one iteration of the loop operation; and
the threshold is between 750 kilobytes (KB) and 1.5 megabytes (MB).
3. The method of claim 1 , wherein:
the amount of data comprises an aggregate size of multiple copies of the data based on a total number of iterations of the loop operation; and
the threshold is between 70 megabytes (MB) and 150 MB.
4. The method of claim 1 , wherein:
the amount of data comprises a size of the data based on one iteration of the loop operation and an aggregate size of multiple copies of the data based on a total number of iterations of the loop operation; and
the threshold comprises a first threshold and a second threshold.
5. The method of claim 4 , further comprising preventing the data from being written to the memory if:
the size of the data based on one iteration of the loop is greater than or equal to the first threshold; and
the aggregate size of the multiple copies of the data based on the total number of iterations of the loop operation is greater than or equal to the second threshold.
6. The method of claim 1 , wherein the data comprises a string including a NOP code and a shellcode.
7. An electronic device for detecting a heap spray attack, comprising:
a processor;
a computer readable memory communicatively coupled to the processor; and
processing instructions encoded in the computer readable memory, the processing instructions, when executed by the processor, operable to perform operations comprising:
receiving a script from a remote device via a network;
detecting a loop operation in the script that contains a write operation operable to write data to the computer readable memory;
determining an amount of the data operable to be written to the computer readable memory;
based at least on a determination that the data is greater than or equal to a threshold, detecting a potential heap spray attack and preventing the data from being written to the computer readable memory; and
based at least on a determination that the data is less than the threshold, allowing the script to be executed.
8. The electronic device of claim 7 , wherein:
the amount of data comprises a size of the data based on one iteration of the loop operation; and
the threshold is between 750 kilobytes (KB) and 1.5 megabytes (MB).
9. The electronic device of claim 7 , wherein:
the amount of data comprises an aggregate size of multiple copies of the data based on a total number of iterations of the loop operation; and
the threshold is between 70 megabytes (MB) and 150 MB.
10. The electronic device of claim 7 , wherein:
the amount of data comprises a size of the data based on one iteration of the loop operation and an aggregate size of multiple copies of the data based on a total number of iterations of the loop operation; and
the threshold comprises a first threshold and a second threshold.
11. The electronic device of claim 10 , wherein the processing instructions are further operable to perform operations comprising preventing the data from being written to the memory if:
the size of the data based on one iteration of the loop is greater than or equal to the first threshold; and
the aggregate size of the multiple copies of the data based on the total number of iterations of the loop operation is greater than or equal to the second threshold.
12. The electronic device of claim 7 , wherein the data comprises a string including a NOP code and a shellcode.
13. A non-transitory computer readable medium storing instructions for detecting a heap spray attack, the instructions, when executed by a processor, configured to:
receive a script at an electronic device from a remote device via a network;
detect a loop operation in the script that contains a write operation operable to write data to a memory of the electronic device;
determine an amount of the data operable to be written to the memory by the write operation;
based at least on a determination that the data is greater than or equal to a threshold, detecting a potential heap spray attack and prevent the data from being written to the memory; and
based at least on a determination that the data is less than the threshold, allowing the script to be executed.
14. The non-transitory computer readable medium of claim 13 , wherein:
the amount of data comprises a size of the data based on one iteration of the loop operation; and
the threshold is between 750 kilobytes (KB) and 1.5 megabytes (MB).
15. The non-transitory computer readable medium of claim 13 , wherein:
the amount of data comprises an aggregate size of multiple copies of the data based on a total number of iterations of the loop operation; and
the threshold is between 70 megabytes (MB) and 150 MB.
16. The non-transitory computer readable medium of claim 13 , wherein:
the amount of data comprises a size of the data based on one iteration of the loop operation and an aggregate size of multiple copies of the data based on a total number of iterations of the loop operation; and
the threshold comprises a first threshold and a second threshold.
17. The non-transitory computer readable medium of claim 16 , wherein the instructions are further configured to prevent the data from being written to the memory if:
the size of the data based on one iteration of the loop is greater than or equal to the first threshold; and
the aggregate size of the multiple copies of the data based on the total number of iterations of the loop operation is greater than or equal to the second threshold.
18. The non-transitory computer readable medium of claim 13 , wherein the data comprises a string including a NOP code and a shellcode.
19. A method for detecting a heap spray attack, comprising:
receiving a script at an electronic device from a remote device via a network;
detecting a loop operation in the script that contains a write operation operable to write a string to a memory of the electronic device;
determining a size of the string operable to be written to the memory by the write operation based on one iteration of the loop operation;
determining an aggregate size of multiple copies of the string operable to be written to the memory by the write operation based on a total number of iterations of the loop operation;
based at least on a determination that the size of the string is greater than or equal to a first threshold and the aggregate size of the multiple copies of the string is greater than or equal to a second threshold, detecting a potential heap spray attack and preventing the string from being written to the memory; and
based at least on a determination that the size of the string is less than a first threshold or the aggregate size of the multiple copies of the string is less than a second threshold, allowing the string to be written to the memory.
20. The method of claim 19 , wherein:
the first threshold is between 750 kilobytes (KB) and 1.5 megabytes (MB); and
the second threshold is between 70 megabytes (MB) and 150 MB.
21. The method of claim 19 , wherein the string comprises a NOP code and a shellcode.
22. The method of claim 19 , wherein the write operation comprises a concatenation operation.
23. The method of claim 19 , wherein the script is a JavaScript or a VBScript.
24. A non-transitory computer readable medium storing instructions for protecting an electronic device, the instructions, when executed by a processor, configured to:
detect a script received at an electronic device from a remote device via a network;
detect a loop operation in the script that contains a write operation operable to write a string to a memory of the electronic device;
determine a size of the string operable to be written to the memory by the write operation based on one iteration of the loop operation;
determine an aggregate size of multiple copies of the string operable to be written to the memory by the write operation based on a total number of iterations of the loop operation;
based at least on a determination that the size of the string is greater than or equal to a first threshold and the aggregate size of the multiple copies of the string is greater than or equal to a second threshold, detecting a potential heap spray attack and preventing the string from being written to the memory; and
based at least on a determination that the size of the string is less than a first threshold or the aggregate size of the multiple copies of the string is less than a second threshold, allowing the string to be written to the memory.