W32.AJM.Worm

SUMMARY

W32.AJM.Worm is a mass-mailing worm. It uses Microsoft Outlook to send itself to email addresses that it retrieves from all unread email messages. The subject line and message body of the email are written in Korean. The attachment file name may also contain Korean characters. The following are some attachment names:

• Heddink.exe
• Go Korea.exe
• RedDevil.exe
• WorldCup.exe
• 2002.exe

Protection

• Virus Definitions (LiveUpdate™ Weekly) August 7, 2002
• Virus Definitions (Intelligent Updater) August 2, 2002

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Low
• Payload Trigger: If the day of the week is Thursday, the worm displays a message. The text is written in Korean. The title of the message is, Message From A If the month is June, it displays a message each time that it runs. The text contains some Korean characters and Here We Go! World Cup Corea! If the month is December, it restores all maximized windows to their previous size, and it opens a window. If the month is November, It swaps the mouse button each time that it runs. If the date is July 7th, it keeps on setting the cursor to a particular position. If the date is January 1st, it confines the cursor to a rectangular area on the screen.
• Large Scale E-mailing: Sends itself to email addresses that it retrieves from all unread email messages.

Distribution

• Distribution Level: Medium
• Subject of Email: [Korean text]
• Name of Attachment: Heddink.exe Go Korea.exe RedDevil.exe WorldCup.exe 2002.exe (There also may be Korean characters.)
• Size of Attachment: 176,173 bytes

TECHNICAL DETAILS

When W32.AJM.Worm is executed, it does the following:

It copies itself to the C:\%system% folder. The file name is randomly-chosen from a list carried by the worm. Some of the file names contain Korean characters. Some examples of the file names are:

• User32Rem.exe
• UserGDL.exe
• BihUpdate.exe
• SysRtw32.exe
• Win32Dll.exe
• MsCrt32.exe
• Temp32.exe    

It then adds a value that refers to this file in the registry key

HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun

This causes the worm to run when you restart Windows.

The worm retrieves email addresses from all unread email messages. It then uses Microsoft Outlook to send itself to all email addresses it finds. The subject line and message of the email are written in Korean. The email message also contains the text

....GO Go 2002 World Cup Corea!!

The attachment name may also contain Korean characters. Some possible attachment names are

• Heddink.exe
• Go Korea.exe
• RedDevil.exe
• WorldCup.exe
• 2002.exe

If the day of the week is Thursday, the worm displays a message. The text is written in Korean. The title of the message is,

Message From A

If the month is June, it displays a message each time that it runs. The text contains some Korean characters and

Here We Go! World Cup Corea!

If the month is December, it restores all maximized windows to their previous size, and it opens a window.

If the month is November, It swaps the mouse button each time that it runs.

If the date is July 7th, it keeps on setting the cursor to a particular position.

If the date is January 1st, it confines the cursor to a rectangular area on the screen.

Recommendations

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.

REMOVAL

NOTE: These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

1. Update the virus definitions, run a full system scan, and delete all of the files that are detected as W32.AJM.Worm.
2. Delete the value that the worm added to the registry key
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun

For details on how to do this, read the following instructions.

To scan for and delete the infected files:

1. Obtain the most recent virus definitions. There are two ways to do this:
   • Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions have undergone full quality assurance testing by Symantec Security Response and are posted to the LiveUpdate servers one time each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
   • Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions have undergone full quality assurance testing by Symantec Security Response. They are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.
     
     Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.
     
2. Start your Symantec antivirus program, and make sure that it is configured to scan all files.
   • Norton AntiVirus Consumer products: Read the document How to configure Norton AntiVirus to scan all files.
   • Symantec Enterprise antivirus products: Read the document How to verify a Symantec Corporate antivirus product is set to scan All Files.
3. Run a full system scan.
4. If any files are detected as infected by W32.AJM.Worm, write down the name of the files, and then click Delete.

To remove the value from the registry:

CAUTION: Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to make a backup of the Windows registry for instructions.

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_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
4. In the right pane, look for a value that refers to any of the files that were detected as W32.AJM.Worm, and delete it.
5. Exit the Registry Editor..