BKDR_WOLYX.TYT
Trojan-PWS.Win32.Hangame.cl (Ikarus)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This malware checks if it is injected to certain processes.
It checks if it is injected to certain Web browsers.
It is capabable of executing certain commands.
This backdoor may be dropped by other malware.
It deletes itself after execution.
TECHNICAL DETAILS
Arrival Details
This backdoor may be dropped by the following malware:
- TROJ_MDROP.TYT
- TROJ_HUPIGO.RUD
Installation
This backdoor drops a copy of itself in the following folders using different file names:
- %User Temp\{Random filename and extension}
It drops the following component file(s):
- %Program Files%\Common Files\Microsoft Shared\OFFICE12\MSO32.DLL - detected as BKDR_WOLYX.TYT
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)
It creates the following folders:
- %System Root%\Users\Public\{AFAFB2EE-837C-4EA5-B933-998F94AEC654}
- %System Root%\ProgramData\{AFAFB2EE-837C-4EA5-B933-998F94AEC654}
- %Windows%\TEMP\TEMP
- %Program Files%\Common Files\Microsoft Shared\OFFICE12
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %Program Files% is the default Program Files folder, usually C:\Program Files.)
Other System Modifications
This backdoor adds the following registry entries as part of its installation routine:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\Session Manager
PendingFileRenameOperations = %User Temp\{Random filename and extension}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinSock2\mswsock32
1001 = %SystemRoot%\system32\mswsock.dll
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinSock2\mswsock32
1002 = %SystemRoot%\system32\mswsock.dll
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinSock2\mswsock32
1003 = %SystemRoot%\system32\mswsock.dll
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinSock2\mswsock32
1004 = %SystemRoot%\system32\rsvpsp.dll
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinSock2\mswsock32
1005 = %SystemRoot%\system32\rsvpsp.dll
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinSock2\mswsock32
PathName = %Program Files%\Common Files\Microsoft Shared\OFFICE12\MSO32.DLL
Other Details
This backdoor connects to the following possibly malicious URL:
- {BLOCKED}.{BLOCKED}.172.177
It deletes itself after execution.
NOTES:
It checks if it is injected to the following processes:
- 360sd.exe
- 360rp.exe
- 360safe.exe
- 360tray.exe
- avp.exe
- dsmain.exe
- dumprep.exe
It checks if it is injected to the following Web browsers:
- firefox.exe
- maxthon.exe
- ttraveler.exe
- theworld.exe
It is capabable of the following commands:
- Command Shell
- Create/Delete Directories
- Create/Read/Delete Files
- Get System Info
- Create/Terminate Process
- Key Logging
- Take ScreenShot
SOLUTION
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Remove malware/grayware files that dropped/downloaded BKDR_WOLYX.TYT
- TROJ_MDROP.TYT
- TROJ_HUPIGO.RUD
Step 3
Restart in Safe Mode
Step 4
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager
- PendingFileRenameOperations = "%User Temp\{Random filename and extension}"
- PendingFileRenameOperations = "%User Temp\{Random filename and extension}"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinSock2\mswsock32
- 1001 = "%SystemRoot%\system32\mswsock.dll"
- 1001 = "%SystemRoot%\system32\mswsock.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinSock2\mswsock32
- 1002 = "%SystemRoot%\system32\mswsock.dll"
- 1002 = "%SystemRoot%\system32\mswsock.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinSock2\mswsock32
- 1003 = "%SystemRoot%\system32\mswsock.dll"
- 1003 = "%SystemRoot%\system32\mswsock.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinSock2\mswsock32
- 1004 = "%SystemRoot%\system32\rsvpsp.dll"
- 1004 = "%SystemRoot%\system32\rsvpsp.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinSock2\mswsock32
- 1005 = "%SystemRoot%\system32\rsvpsp.dll"
- 1005 = "%SystemRoot%\system32\rsvpsp.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinSock2\mswsock32
- PathName = "%Program Files%\Common Files\Microsoft Shared\OFFICE12\MSO32.DLL"
- PathName = "%Program Files%\Common Files\Microsoft Shared\OFFICE12\MSO32.DLL"
Step 5
Search and delete these folders
- %System Root%\Users\Public\{AFAFB2EE-837C-4EA5-B933-998F94AEC654}
- %System Root%\ProgramData\{AFAFB2EE-837C-4EA5-B933-998F94AEC654}
- %Windows%\TEMP\TEMP
- %Program Files%\Common Files\Microsoft Shared\OFFICE12
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_WOLYX.TYT. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
Did this description help? Tell us how we did.