Trend Micro OfficeScan 11.0/XG (12.0) - Image File Execution Bypass Vulnerability

[+] 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.


#  0day.today [2018-04-04]  #