MemoryMon

Introduction

MemoryMon is able to detect execution of kernel memory where is not backed by any image file (kernel modules) using extended page table (EPT). It can help researchers analyze kernel mode code installs and runs code outside of an image file.

A demo video using MemoryMon against Turla rootkit can be found in Youtube:

https://www.youtube.com/watch?v=O5_ocsplrfA

MemoryMon is implemented on the top of HyperPlatform. See a project page for more details of HyperPlatform:

https://github.com/tandasat/HyperPlatform

Installation and Uninstallation

On the x64 platform, you have to enable test signing to install the driver. To do that, open the command prompt with the administrator privilege and type the following command, and then restart the system to activate the change:

bcdedit /set {current} testsigning on

To install and uninstall the driver, use the 'sc' command. For installation:

>sc create MemoryMon type= kernel binPath= C:\Users\user\Desktop\MemoryMon.sys
>sc start MemoryMon

And for uninstallation:

>sc stop MemoryMon
>sc delete MemoryMon

Note that the system must support the Intel VT-x and EPT technology to successfully install the driver.

To install the driver on a virtual machine on VMware Workstation, see an "Using VMware Workstation" section in the HyperPlatform User's Documents found in its project page.

https://github.com/tandasat/HyperPlatform/tree/master/Documents

Output

All logs are printed out to DbgView and saved in C:\Windows\MemoryMon.log.

On a 64bit Windows, activities of PatchGuard are usually observed. The following are those logs seen on Windows 7 system.

08:47:07.276	INF	#0	    4	    0	System         	[EXEC] *** VA = FFFFFA800194A468, PA = 000000007fe89468, Return = FFFFF80002AD8C1C, ReturnBase = FFFFF80002A5A000
08:47:07.276	INF	#0	    4	    0	System         	[EXEC] *** VA = FFFFFA8003D46007, PA = 000000007db46007, Return = FFFFFA800194A4AD, ReturnBase = 0000000000000000
08:47:07.276	INF	#0	    4	    0	System         	[EXEC] *** VA = FFFFFA8003D47580, PA = 000000007db47580, Return = FFFFFA8003D460B0, ReturnBase = 0000000000000000
08:47:07.291	INF	#0	    4	   64	System         	[EXEC] *** VA = FFFFFA8003D4AE1C, PA = 000000007db4ae1c, Return = FFFFF80002AD7B69, ReturnBase = FFFFF80002A5A000
08:47:07.291	INF	#0	    4	   64	System         	[EXEC] *** VA = FFFFFA8003D4856B, PA = 000000007db4856b, Return = 0000000000000004, ReturnBase = 0000000000000000

The first line indicates that a virtual address FFFFFA800194A468 is executed and its potential return address is FFFFF80002AD8C1C. Since execution of a non-image region is not always triggered by the CALL instruction, a reported return address can be wrong. For instance, the last line reports return address 0000000000000004.

Note that symbols names can be resolved with hyperplatform_log_parser. The above logs are parsed as followings, for example:

08:47:07.276     4:    0 executed fffffa800194a468, will return to fffff80002ad8c1c nt!KiRetireDpcList+0x1bc
08:47:07.276     4:    0 executed fffffa8003d46007, will return to fffffa800194a4ad
08:47:07.276     4:    0 executed fffffa8003d47580, will return to fffffa8003d460b0
08:47:07.291     4:   64 executed fffffa8003d4ae1c, will return to fffff80002ad7b69 nt!ExpWorkerThread+0x111
08:45:07.265     4:   64 executed fffffa8002626629, will return to                4

See a project page for more details.

https://github.com/tandasat/hyperplatform_log_parser

Supported Platforms

x86 and x64 Windows 7, 8.1 and 10
The system must support the Intel VT-x and EPT technology

License

This software is released under the MIT License, see LICENSE.

N3mes1s / MemoryMon