W32.Goner.A@mm

Due to a decreased number of submissions, Symantec Security Response is downgrading W32.Goner.A@mm from a threat rating of Category 3 to Category 2. W32.Goner.A@mm is a mass-mailing worm that is written in Visual Basic. The worm has been compressed using a Portable Executable (PE) file compressor. The worm can spread its infection using the ICQ network as well as by email using Microsoft Outlook. If IRC is installed, this worm can also insert mIRC scripts that will enable the computer to be used in Denial of Service (DOS) attacks. The IRC channel used for controlling the worm is currently blocked, preventing this functionality.

Also Known As:	I-Worm.Goner [Kaspersky], W32/Goner@MM [McAfee], WORM_GONER.A [Trend], W32/Goner-A [Sophos], Win32.Goner.A [Computer Associates]
Type:	Worm
Infection Length:	38,912 bytes
Systems Affected:	Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows XP
Systems Not Affected:	DOS, Linux, Macintosh, OS/2, UNIX, Windows 3.x

Virus Definitions (LiveUpdate™ Weekly) December 04, 2001 Virus Definitions (Intelligent Updater) December 04, 2001

Wild Number of infections: More than 1000 Number of sites: More than 10 Geographical distribution: High Threat containment: Easy Removal: Moderate

Threat Metrics Wild: Low Damage: Medium Distribution: High

Damage

• Payload: Upon execution
  • Large scale e-mailing: Send itself to all users in Outlook Address Books
  • Deletes files: Attempts to delete antivirus and firewall software

Distribution

• Subject of email: Hi
• Name of attachment: Gone.scr
• Size of attachment: 38,912 bytes

This attachment will not be executed by viewing the message in the preview pane. The attachment must be executed to begin delivering its payload. Upon execution, W32.Goner.A@mm starts by displaying the following window.



In the background, the worm sends itself to all addresses in the the Microsoft Outlook address book. The email appears as follows.



The worm has been packed using a known Portable Executable (PE) packer. The size of the unpacked worm is approximately 159 KB.

The worm adds the value

C:\%SYSTEM%\gone.scr C:\%SYSTEM%\gone.scr

to the registry key

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

NOTES:

• %SYSTEM% is the path to the Windows System folder. In most cases this would be C:\Windows\System; however, the location could be different if the Windows System folder has been installed to a different location.
• The value is the same as the value as the name of the file (the value data) that is being called.

• Aplica32.exe
• Avconsol.exe
• Avp.exe
• Avp32.exe
• Avpcc.exe
• Avpm.exe
• Cfiadmin.exe
• Cfiaudit.exe
• Cfinet32.exe
• Esafe.exe
• Frw.exe
• Icload95.exe
• Icloadnt.exe
• Icmon.exe
• Icsupp95.exe
• Icsuppnt.exe
• Lockdown2000.exe
• Navapw32.exe
• Navw32.exe
• Pcfwallicon.exe
• Safeweb.exe
• Tds2-98.exe
• Tds2-Nt.exe
• Vsecomr.exe
• Vshwin32.exe
• Vsstat.exe
• Webscanx.exe
• Zonealarm.exe
• _Avp32.exe
• _Avpcc.exe
• _Avpm.exe

1. Check for the version of the ICQ .dll file that contains the APIs that will be used. If the correct version is found, the worm proceeds.
2. Retrieve a list of all "buddies" who are currently online.
3. Retrieve information about each user individually. This information is required to be able to send files.
4. Send itself to all users on the list.

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
• Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
• Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.

The preferred way to remove this worm is to use the removal tool. If that is not an option in your situation, you must remove the worm manually.

Removal Tool
Symantec Security Response has posted a removal tool to assist in eradicating this worm. Please go to the following Web site to read the instructions and download the removal tool:

http://securityresponse.symantec.com/avcenter/venc/data/w32.goner.a@mm.removal.tool.html


Manual Removal

An online tutorial on how to manually remove W32.Goner.A@mm is available here.

To manually remove this worm, you must restart the computer in Safe mode or end the process on the part of the worm that is running in memory. Then reverse the changes that the worm made to the registry, restart the computer, reinstall Norton AntiVirus, and then run a full system scan and delete all infected files. Detailed instructions follow.

Follow the instructions for your version of Windows.

Windows 95/98/Me
Because the worm file may be in use, you must restart in Safe mode to remove the changes made to the registry.

CAUTION: (For Windows Me users only.) If you are running Windows Me, follow the instructions in the section System Restore option in Windows Me at the end of this document before you begin the removal procedure.

Restart the computer in Safe mode by following the instructions in How to restart Windows 9x or Windows Me in Safe mode.

NOTE: Shut down the computer for a full 30 seconds before restarting in Safe Mode to make sure the worm has been cleared from memory.

Windows NT/2000/XP
Because the worm file may be in use, you must End Process on the worm files before the registry value can be removed.

1. Press Ctrl+Alt+Delete one time.
2. Click Task Manager.
3. Click the Processes tab.
4. Click the "Image Name" column header two times to sort the processes alphabetically.
5. Scroll through the list and look for gone.scr. If you find the file, click it and then click End Process.
6. Scroll through the list and look for pentagone. If you find the file, click it and then click End Process.
7. Close the Task Manager.

1. Click Start, and click Run. The Run dialog box appears.
2. Type regedit and then click OK. The Registry Editor opens.
3. Navigate to the following key:
   
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
   
4. In the right pane, delete the following value:
   
   C:\%SYSTEM%\gone.scr C:\%SYSTEM%\gone.scr
   
   NOTE: %SYSTEM% is the path to the Windows System folder. In most cases this would be C:\Windows\System; however, the location could be different if the Windows System folder has been installed to a different location.
   
5. Click Registry, and click Exit.
6. Restart the computer.
7. Reinstall NAV, and restart the computer.

1. Run LiveUpdate to make sure that you have the most recent virus definitions.
   
   CAUTION: If the worm has successfully deleted the target Norton AntiVirus files, you must uninstall and then reinstall Norton AntiVirus before you can run LiveUpdate or remove the worm using Norton AntiVirus. If Norton AntiVirus was installed as part of another Symantec program, such as System Works or Norton Internet Security, you must uninstall and reinstall those as well. Read the instructions in the section How to uninstall and reinstall your Symantec software before you continue.When finished, return to this section and complete the removal procedure.
   
2. Start Norton AntiVirus (NAV), and make sure that NAV is configured to scan all files. For instructions on how to do this, read the document How to configure Norton AntiVirus to scan all files.
3. Run a full system scan.
4. Delete all files that are detected as W32.Goner.A@mm. Deleted files must be either replaced from a clean backup or reinstalled.

Additional information:

How to uninstall and reinstall your Symantec software
This is necessary if the worm has successfully deleted the Norton AntiVirus program files. Read the instructions that apply to your situation.

Norton AntiVirus is installed by itself
If you have installed only Norton AntiVirus, and it is not part of SystemWorks or Norton Internet Security, follow these instructions.

1. Uninstall Norton AntiVirus from the Add/Remove programs applet of the Windows Control Panel. You may or may not see error messages.
2. Restart the computer.
3. Carefully follow all of the instructions in the document How to uninstall Norton AntiVirus using the Rnav.exe removal tool.
4. Restart the computer.
5. Reinstall Norton AntiVirus from the installation CD or the downloaded installation files.

1. Uninstall Norton SystemWorks or Norton Internet security (or both if both are installed) from the Add/Remove programs applet of the Windows Control Panel. Choose to uninstall all components. You may or may not see error messages.
2. Restart the computer.
3. Carefully follow all of the instructions in the document How to uninstall Norton AntiVirus using the Rnav.exe removal tool.
4. Restart the computer.
5. Reinstall your Symantec programs from the installation CD or the downloaded installation files.
   
   NOTE: If you have problems or see error message when reinstalling either Norton SystemWorks or Norton Internet Security, read one--or both--of the following documents:
   • If you have Norton SystemWorks installed, follow the instructions in the document How to use the Norton SystemWorks cleanup utility (SymClean). Restart the computer when finished.
   • If you have Norton Internet Security installed, follow the instructions in the document How to uninstall Norton Internet Security or Personal Firewall using the Rnis.exe removal tool. Restart the computer when finished.
     
6. Return to the section Remove the worm files and start with the first step.

1. Close all open programs. Then right-click My Computer on the Windows desktop
2. Click Properties.
3. Click the Performance tab.
4. Click File System.
5. Click the Troubleshooting tab.
6. Check Disable System Restore.
7. Click OK.
8. Click OK.
9. Click Yes to restart. The System Restore feature is disabled and the contents of the _RESTORE folder are purged when the system is restarted.
   
   NOTE: After following all of the removal instructions, repeat steps 1 through 9, except in step 6 uncheck Disable System Restore.

For additional information and an alternative to disabling System Restore, see the Microsoft Knowledge Base article Anti-Virus Tools Cannot Clean Infected Files in the _Restore Folder, Article ID: Q263455.

Write-up by: Neal Hindocha