- Threat Encyclopedia
- Malware
- VBS_GROUCH.A
Windows 2000, XP, Server 2003
Propagates via removable drives, Propagates via email
It checks if it has already infected the Microsoft Word global template, Normal.dot by checking for the existence of a registry key.
Infected document files are detected by Trend Micro as WM_GROUCH.A.
It propagates via email by sending a copy of itself to addresses found in the Microsoft Outlook address book.
It then deletes each message as they are sent.
It keeps a list of all email address that it has sent in a certain registry key.
It deletes all files in the %Windows% folder if the current date is May 9 and displays a message box.
This worm arrives as attachment to mass-mailed email messages. It arrives via removable drives.
It gathers target email addresses from cached email, address books, and mailboxes.
23,004 bytes
VBS
Yes
13 Mar 2003
Modifies files
Arrival Details
This worm arrives as attachment to mass-mailed email messages.
It arrives via removable drives.
It may arrive via network shares.
Installation
This worm drops the following files:
(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.)
It drops the following copies of itself into the affected system:
(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.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
MSGrc32 = Wscript.exe %System%\MSGrc32.vbs %1
Other System Modifications
This worm adds the following registry entries as part of its installation routine:
HKEY_CURRENT_USER\Software\Zed/[rRlf]\
Grouch\1.0
RndCopy = {file name of copy in %Startup% folder}
HKEY_CURRENT_USER\Software\Zed/[rRlf]\
Grouch\1.0\NormalTemplate
(Default) = {day of infection}
HKEY_CURRENT_USER\Software\Microsoft\
Office\{Application Version}\Word\
Security
Level = 1
HKEY_CURRENT_USER\Software\Zed/[rRlf]\
Grouch\1.0
(Default) = VBS/Grouch by Zed/[rRlf]
HKEY_CURRENT_USER\Software\Microsoft\
Office\{Application Version}\Word\
Security
AccessVBOM = 1
It adds the following registry keys as part of its installation routine:
HKEY_CURRENT_USER\Software\Zed/[rRlf]
HKEY_CURRENT_USER\Software\Zed/[rRlf]\
Grouch
HKEY_CURRENT_USER\Software\Zed/[rRlf]\
Grouch\1.0
HKEY_CURRENT_USER\Software\Zed/[rRlf]\
Grouch\1.0\NormalTemplate
HKEY_CURRENT_USER\Software\Zed/[rRlf]\
Grouch\1.0\Outlook
HKEY_CURRENT_USER\Software\Zed/[rRlf]\
Grouch\1.0\Outlook\
RecordContacts
Propagation
This worm drops copies of itself into the following folders used in peer-to-peer (P2P) networks:
It drops the following copy of itself in all physical and removable drives:
It gathers target email addresses from cached email, address books, and mailboxes.
Other Details
This worm does the following:
8.900
1.483.24
13 Mar 2003
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 files dropped/downloaded by VBS_GROUCH.A
Step 3
Delete this registry key
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.
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.
Step 5
Scan your computer with your Trend Micro product to delete files detected as
VBS_GROUCH.A
*Note: 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.
Step 6
Restore files from backup Only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on your computer again.