VBS_GOODWORM.NIL
Windows
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Worm arrives via removable drives. 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 drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
TECHNICAL DETAILS
Arrival Details
This Worm arrives via removable drives.
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 Worm drops the following copies of itself into the affected system:
- %System%\domz.vbs (modified copy)
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It drops the following files:
- {Drive Letter}:\domz_info.txt
Autostart Technique
This Worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
domz = "Wscript.exe %System%\domz.vbs"
Other System Modifications
This Worm modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = 0
(Note: The default value data of the said registry entry is {user defined}.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoRun = 0
(Note: The default value data of the said registry entry is {user defined}.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoFolderOptions = 0
(Note: The default value data of the said registry entry is {user defined}.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoViewOnDrive = 0
(Note: The default value data of the said registry entry is {user defined}.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableRegistryTools = 0
(Note: The default value data of the said registry entry is {user defined}.)
HKEY_CURRENT_USER\Software\Policies\
Microsoft\Windows\System
DisableCMD = 0
(Note: The default value data of the said registry entry is {user defined}.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoAddPrinter = 0
(Note: The default value data of the said registry entry is {user defined}.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoLogoff = 0
(Note: The default value data of the said registry entry is {user defined}.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoNetworkConnections = 0
(Note: The default value data of the said registry entry is {user defined}.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoDesktop = 0
(Note: The default value data of the said registry entry is {user defined}.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoDriveTypeAutorun = 255
(Note: The default value data of the said registry entry is {user defined}.)
Propagation
This Worm drops the following copy of itself in all physical and removable drives:
- {Drive Letter}:\domz_maintenance.vbs (modified copy)
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
[Autorun]
open=wscript.exe domz_maintenance.vbs
shell\Open\Command=wscript.exe domz_maintenance.vbs
shell\Open\Default=1
shell\AutoPlay\Command=wscript.exe domz_maintenance.vbs
shell\Explore\Command=wscript.exe domz_maintenance.vbs
SOLUTION
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Identify and terminate files detected as VBS_GOODWORM.NIL
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- domz = "Wscript.exe %System%\domz.vbs"
- domz = "Wscript.exe %System%\domz.vbs"
Step 5
Restore this modified 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
- From: DisableTaskMgr = 0
To: DisableTaskMgr = {user defined}
- From: DisableTaskMgr = 0
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- From: NoRun = 0
To: NoRun = {user defined}
- From: NoRun = 0
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- From: NoFolderOptions = 0
To: NoFolderOptions = {user defined}
- From: NoFolderOptions = 0
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- From: NoViewOnDrive = 0
To: NoViewOnDrive = {user defined}
- From: NoViewOnDrive = 0
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
- From: DisableRegistryTools = 0
To: DisableRegistryTools = {user defined}
- From: DisableRegistryTools = 0
- In HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\System
- From: DisableCMD = 0
To: DisableCMD = {user defined}
- From: DisableCMD = 0
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- From: NoAddPrinter = 0
To: NoAddPrinter = {user defined}
- From: NoAddPrinter = 0
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- From: NoLogoff = 0
To: NoLogoff = {user defined}
- From: NoLogoff = 0
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- From: NoNetworkConnections = 0
To: NoNetworkConnections = {user defined}
- From: NoNetworkConnections = 0
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- From: NoDesktop = 0
To: NoDesktop = {user defined}
- From: NoDesktop = 0
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- From: NoDriveTypeAutorun = 255
To: NoDriveTypeAutorun = {user defined}
- From: NoDriveTypeAutorun = 255
Step 6
Search and delete this file
- {Drive Letter}:\domz_info.txt
Step 7
Search and delete AUTORUN.INF files created by VBS_GOODWORM.NIL that contain these strings
- [Autorun]
- open=wscript.exe domz_maintenance.vbs
- shell\Open\Command=wscript.exe domz_maintenance.vbs
- shell\Open\Default=1
- shell\AutoPlay\Command=wscript.exe domz_maintenance.vbs
- shell\Explore\Command=wscript.exe domz_maintenance.vbs
Step 8
Scan your computer with your Trend Micro product to delete files detected as VBS_GOODWORM.NIL. 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.
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