CHM_DROPPER.VTG
Exploit-CodeBase.chm (McAfee); TR/Dropper.Gen (AntiVir)
Windows 2000, Windows XP, Windows Server 2003

Threat Type: Trojan
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This Trojan arrives as attachment to mass-mailed email messages. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It connects to certain URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats. As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
Arrival Details
This Trojan arrives as attachment to mass-mailed email messages.
It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This Trojan drops the following files:
- %Windows%\Downloaded Program Files\comctr.inf
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)
It drops and executes the following files:
- %System%\comctr.dll
- %System%\oci.dll
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
Other System Modifications
This Trojan modifies the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\MSDTC
Start = 2
(Note: The default value data of the said registry entry is 3.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\MSDTC
ObjectName = LocalSystem
(Note: The default value data of the said registry entry is NT AUTHORITY\NetworkService.)
Download Routine
This Trojan connects to the following malicious URLs:
- http://jpgame.{BLOCKED}et.org
As of this writing, the said sites are inaccessible.
SOLUTION
NOTES:
Trend customers:
Keep your pattern and scan engine files updated. Trend Micro antivirus software can clean or remove most types of computer threats. Malware, though, such as Trojans, scripts, overwriting viruses and joke programs which are identified as uncleanable, should simply be deleted.
All Internet users:
- Use HouseCall - the Trend Micro online threat scanner to check for malware that may already be on your PC.
- Catch malware/grayware before they affect your PC or network. Secure your Web world with Trend Micro products that offer the best anti-threat and content security solutions for home users, corporate users, and ISPs. Go here for more information on Trend Micro products that fit your needs.
Did this description help? Tell us how we did.