[+] Credits: John Page (aka hyp3rlinx)  
[+] Website: hyp3rlinx.altervista.org
[+] Source:  http://hyp3rlinx.altervista.org/advisories/TRENDMICRO-OFFICESCAN-XG-IMAGE-FILE-EXECUTION-BYPASS.txt
[+] ISR: ApparitionSec            
 


Vendor:
==================
www.trendmicro.com



Product:
========
OfficeScan 
v11.0 and XG (12.0)*


OfficeScan protects enterprise networks from malware, network viruses, web-based threats, spyware, and mixed threat attacks.
An integrated solution, OfficeScan consists of the OfficeScan agent program that resides at the endpoint and a server program that
manages all agents. The OfficeScan agent guards the endpoint and reports its security status to the server. The server, through the
web-based management console, makes it easy to set coordinated security policies and deploy updates to every agent.


Vulnerability Type:
===================
Image File Execution Bypass



CVE Reference:
==============
N/A



Security Issue:
================
OfficeScan XG "Unauthorized Change Prevention Service" is a Local SYSTEM service that is supposed to protect OfficeScan processes
like "PccNTMon.exe" from being terminated, and also prevents unauthorized arbitrary registry settings being made to the protected
machine even by an Administrator.

However, we can easily bypass by exploiting Windows Image File Execution Options (IFEO) to hijack the service process.
IFEO has been used by malwares for some time to prevent process from running or execute a process of an attackers choosing in
place of the process the user expects.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options

All an attacker needs to do is create a registry key in IFEO with the same name as "TMBMSRV.exe" which is used by the
"Trend Micro Unauthorized Change Prevention Service" SYSTEM service. After creating this registry key we create a "string value"
named debugger pointing to say "calc.exe", we wait and once system reboots BOOM!


References:
===========
https://success.trendmicro.com/solution/1118372



Exploit/POC:
=============

Reproduction:

1) Open registry 

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options

2) Create a new Key with no name

3) Create a new string value under the new key named "debugger" with value of c:\Windows\system32\calc.exe

4) Rename the created key to TMBMSRV.exe 

5) Reboot system

Done!

We can then not only Kill TM but write to TrendMicro whitelist key in the registry for our evil binary to be left alone in peace.



Network Access:
===============
Local



Severity:
=========
High



Disclosure Timeline:
=================================
Vendor Notification: June 28, 2017
Vendor Reply: "Officescan Build 1222 which is affected by this bug was already pulled and is no longer available for public download"
Vendor Reply: "created hotfixes for product improvement."
September 28, 2017 : Public Disclosure



[+] Disclaimer
The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise.
Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and
that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit
is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility
for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information
or exploits by the author or elsewhere. All content (c).

hyp3rlinx