W32.HLLW.Ajja

SUMMARY

The W32.HLLW.Ajja worm attempts to spread across the KaZaA, Grokster, and Edonkey2000 file-sharing networks. This worm also attempts to delete program files belonging to several antivirus programs.

As part of the execution of W32.HLLW.Ajja, a fake "Install" message will prompt you to "Clik!! in Next to Install."

W32.HLLW.Ajja is written in Microsoft Visual Basic, version 6.

NOTE: Virus definitions dated prior to March 5, 2003 may detect this threat as Bloodhound.W32.5.

Protection

• Virus Definitions (LiveUpdate™ Weekly) March 5, 2003
• Virus Definitions (Intelligent Updater) March 5, 2003

Threat Assessment

Wild

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

Damage

• Damage Level: Medium
• Compromises Security Settings: Attempts to delete program files belonging to several antivirus programs.

Distribution

• Distribution Level: Medium
• Shared Drives: Attempts to spread across the KaZaA, Grokster, and Edonkey2000 file-sharing networks.

TECHNICAL DETAILS

When W32.HLLW.Ajja is executed, it does the following:

1. Creates the file, C:Ini.bat, and then executes it. When Ini.bat is run, the worm creates 10 folders on the C drive. Neither Ini.bat nor the created folders are malicious.
   
2. Attempts to copy itself as the following files:
   • C:WindowsRilk-Tester.exe
   • C:WindowsDetection.exe
   • C:WindowsScreensaver.exe
   • C:WindowsMsn.exe
   • C:WindowsAntivirus.exe
   • C:WindowsCommandRilk.exe
     
     NOTE: This copy routine fails on Windows NT/2000.
     
3. Copies itself as the following files:
   
   NOTE: All the destination folders belong to file-sharing programs.
   
   • C:Archivos de programaKaZaAMy Shared FolderPorto_seguro_video.exe
   • C:Archivos de programaKaZaAMy Shared FolderFestival de via_2003.exe
   • C:Archivos de programaKaZaAMy Shared FolderHots pics of britney.exe
   • C:Archivos de programaKaZaAMy Shared FolderChile.exe
   • C:Archivos de programaKaZaAMy Shared FolderWindows XP complete + serial.exe
   • C:Archivos de programaKaZaAMy Shared FolderAll programs all cracks.exe
   • C:Archivos de programaKaZaAMy Shared FolderScreen saver christina aguilera.exe
   • C:Archivos de programaKaZaAMy Shared FolderScreen saver christina aguilera naked.exe
     
   • C:Archivos de programaGroksterMy GroksterCrack all.exe
   • C:Archivos de programaGroksterMy GroksterVisual basic 6.exe
   • C:Archivos de programaGroksterMy GroksterChile.exe
   • C:Archivos de programaGroksterMy GroksterStarcraft serial.exe
   • C:Archivos de programaGroksterMy GroksterVisual basic 6 crack.exe
   • C:Archivos de programaGroksterMy GroksterCrack for porno programs.exe
   • C:Archivos de programaGroksterMy GroksterAll acces porn.exe
     
   • C:Archivos de programaEdonkey2000IncomingPer 60 crack.exe
   • C:Archivos de programaEdonkey2000IncomingPER 60.exe
   • C:Archivos de programaEdonkey2000IncomingMsn all versions.exe
   • C:Archivos de programaEdonkey2000IncomingPak of porn gif.exe
     
     
4. Adds these values:
   
   rilk C:windowsilk-tester.exe
   Power of BAT c:ini.bat
   
   to the registry key:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
   
   so that the worm runs when you start Windows.
   
5. Adds the value:
   
   chile c:windowsdetection.exe
   
   to the registry key:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersion
   RunServices
   
   so that the worm runs when you start Windows.
   
6. Attempts to delete the following files:
   • C:AntiViral Toolkit Pro*.*
   • C:Program FilesCommand SoftwareF-PROT95*.*
   • C:Program FilesMcAfeeVirusScan*.*
   • C:Program FilesNorton AntiVirus*.*
   • C:ToolkitFindVirus*.*
   • C:PC-Cillin 95*.*
   • C:PC-Cillin 97*.*
   • C:Tbavw95*.*
   • C:Program FilesKaspersky LabKaspersky Anti-Virus Personal*.*
   • C:Program FilesSophos SWEEP for NT*.*
   • C:Program FilesPanda SoftwarePanda Antivirus Titanium*.*
   • C:Program FilesEset*.*
   • C:Program FilesGrisoftAVG6*.*
   • C:Program FilesVexira*.*
   • C:Archivos de ProgramaTrend PC-cillin 98*.*
   • C:Archivos de ProgramaTrend MicroPC-cillin 2002*.*
   • C:Archivos de ProgramaMcAfeeMcAfee VirusScan*.*
   • C:Archivos de ProgramaPerav*.*
     
     
7. Displays the following fake message:
   
   

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

The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

1. Update the virus definitions.
2. Run a full system scan and delete all the files detected as W32.HLLW.Ajja. Delete the C:Ini.bat file.
3. Delete the values that the worm added to the registry:
   
   

For specific details on each of these steps, read the following instructions.

1. Updating the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:

• Running LiveUpdate, which is the easiest way to obtain the virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate), in the "Protection" section, at the top of this writeup.
• Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater), in the "Protection" section, at the top of this writeup.
  
  The 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. Scanning for and deleting the infected files

1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
   • For Norton AntiVirus consumer products: Read the document, "How to configure Norton AntiVirus to scan all files."
   • For Symantec AntiVirus Enterprise products: Read the document, "How to verify that a Symantec Corporate antivirus product is set to scan All Files."
2. Run a full system scan.
3. If any files are detected as infected with W32.HLLW.Ajja, click Delete.
4. Using Windows Explorer, delete the C:Ini.bat file.

3. Deleting 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 the specified keys only. Read the document, "How to make a backup of the Windows registry," for instructions.

1. Click Start, and then click Run. (The Run dialog box appears.)
2. Type regedit
   
   Then click OK. (The Registry Editor opens.)
   
3. Navigate to the key:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
4. In the right pane, delete the values:
   
   rilk C:windowsilk-tester.exe
   Power of BAT c:ini.bat
   
5. Navigate to the key:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersion
   RunServices
   
   NOTE: This key is not found on all the systems.
   
6. In the right pane, delete the value:
   
   chile c:windowsdetection.exe
   
7. Exit the Registry Editor.