TROJ_DLOADR.BWJ

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CLASSES_ROOT\Cad.Document

HKEY_CLASSES_ROOT\Cad.Document\DefaultIcon

HKEY_CLASSES_ROOT\Cad.Document\shell

HKEY_CLASSES_ROOT\Cad.Document\shell\
open

HKEY_CLASSES_ROOT\Cad.Document\shell\
open\command

HKEY_CLASSES_ROOT\Cad.Document\shell\
print

HKEY_CLASSES_ROOT\Cad.Document\shell\
print\command

HKEY_CLASSES_ROOT\Cad.Document\shell\
printto

HKEY_CLASSES_ROOT\Cad.Document\shell\
printto\command

It adds the following registry entries:

HKEY_CLASSES_ROOT\Cad.Document
Default = "Cad Document"

HKEY_CLASSES_ROOT\Cad.Document
Default = "{malware path}\{malware filename}.exe,0"

HKEY_CLASSES_ROOT\Cad.Document\shell\
open\command
Default = "{malware path}\{malware filename}.exe "%1""

HKEY_CLASSES_ROOT\Cad.Document\shell\
print\command
Default = "{malware path}\{malware filename}.exe /p "%1""

HKEY_CLASSES_ROOT\Cad.Document\shell\
printto\command
Default = "{malware path}\{malware filename}.exe /pt "%1" "%2" "%3" "%4""

Download Routine

This Trojan downloads the file from the following URL and renames the file when stored in the affected system:

• http://{BLOCKED}n-foundation.ro/images/tere.exe
• http://{BLOCKED}ri-gagyi.com/images/tere.exe
• http://{BLOCKED}ni.net/wp-content/uploads/tere.exe
• http://{BLOCKED}tbot.com/bots/tere.exe
• http://{BLOCKED}i.org/wp-content/uploads/2012/02/tere.exe

It saves the files it downloads using the following names:

• %User Temp%\{random file name}.exe - Detected as TSPY_ZBOT.BWJ
• %Temporary Internet Files%\Content.IE5\{random folder name}\tere[1].exe - Detected as TSPY_ZBOT.BWJ

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %Temporary Internet Files% is the Temporary Internet Files folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temporary Internet Files on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Microsoft\Windows\Temporary Internet Files on Windows Vista and 7.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

NOTES:

TROJ_DLOADR.BWJ is executed every time a CAD document is executed or printed.