W32.HLLW.Ajja

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Discovered: March 05, 2003
Updated: February 13, 2007 11:43:47 AM
Type: Worm
Systems Affected: Windows


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.

Antivirus Protection Dates

  • Initial Rapid Release version March 05, 2003
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version March 05, 2003
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date March 05, 2003

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Writeup By: Kaoru Hayashi

Discovered: March 05, 2003
Updated: February 13, 2007 11:43:47 AM
Type: Worm
Systems Affected: Windows


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:\Windows\Rilk-Tester.exe
    • C:\Windows\Detection.exe
    • C:\Windows\Screensaver.exe
    • C:\Windows\Msn.exe
    • C:\Windows\Antivirus.exe
    • C:\Windows\Command\Rilk.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 programa\KaZaA\My Shared Folder\Porto_seguro_video.exe
    • C:\Archivos de programa\KaZaA\My Shared Folder\Festival de via_2003.exe
    • C:\Archivos de programa\KaZaA\My Shared Folder\Hots pics of britney.exe
    • C:\Archivos de programa\KaZaA\My Shared Folder\Chile.exe
    • C:\Archivos de programa\KaZaA\My Shared Folder\Windows XP complete + serial.exe
    • C:\Archivos de programa\KaZaA\My Shared Folder\All programs all cracks.exe
    • C:\Archivos de programa\KaZaA\My Shared Folder\Screen saver christina aguilera.exe
    • C:\Archivos de programa\KaZaA\My Shared Folder\Screen saver christina aguilera naked.exe
    • C:\Archivos de programa\Grokster\My Grokster\Crack all.exe
    • C:\Archivos de programa\Grokster\My Grokster\Visual basic 6.exe
    • C:\Archivos de programa\Grokster\My Grokster\Chile.exe
    • C:\Archivos de programa\Grokster\My Grokster\Starcraft serial.exe
    • C:\Archivos de programa\Grokster\My Grokster\Visual basic 6 crack.exe
    • C:\Archivos de programa\Grokster\My Grokster\Crack for porno programs.exe
    • C:\Archivos de programa\Grokster\My Grokster\All acces porn.exe
    • C:\Archivos de programa\Edonkey2000\Incoming\Per 60 crack.exe
    • C:\Archivos de programa\Edonkey2000\Incoming\PER 60.exe
    • C:\Archivos de programa\Edonkey2000\Incoming\Msn all versions.exe
    • C:\Archivos de programa\Edonkey2000\Incoming\Pak of porn gif.exe

  4. Adds these values:

    rilk C:\windows\rilk-tester.exe
    Power of BAT c:\ini.bat

    to the registry key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

    so that the worm runs when you start Windows.
  5. Adds the value:

    chile c:\windows\detection.exe

    to the registry key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\
    RunServices

    so that the worm runs when you start Windows.
  6. Attempts to delete the following files:
    • C:\AntiViral Toolkit Pro\*.*
    • C:\Program Files\Command Software\F-PROT95\*.*
    • C:\Program Files\McAfee\VirusScan\*.*
    • C:\Program Files\Norton AntiVirus\*.*
    • C:\Toolkit\FindVirus\*.*
    • C:\PC-Cillin 95\*.*
    • C:\PC-Cillin 97\*.*
    • C:\Tbavw95\*.*
    • C:\Program Files\Kaspersky Lab\Kaspersky Anti-Virus Personal\*.*
    • C:\Program Files\Sophos SWEEP for NT\*.*
    • C:\Program Files\Panda Software\Panda Antivirus Titanium\*.*
    • C:\Program Files\Eset\*.*
    • C:\Program Files\Grisoft\AVG6\*.*
    • C:\Program Files\Vexira\*.*
    • C:\Archivos de Programa\Trend PC-cillin 98\*.*
    • C:\Archivos de Programa\Trend Micro\PC-cillin 2002\*.*
    • C:\Archivos de Programa\McAfee\McAfee VirusScan\*.*
    • C:\Archivos de Programa\Perav\*.*

  7. Displays the following fake message:




Recommendations

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

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • 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.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a 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.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. 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.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.

Writeup By: Kaoru Hayashi

Discovered: March 05, 2003
Updated: February 13, 2007 11:43:47 AM
Type: Worm
Systems Affected: Windows


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.
  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_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  4. In the right pane, delete the values:

    rilk C:\windows\rilk-tester.exe
    Power of BAT c:\ini.bat
  5. Navigate to the key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\
    RunServices

    NOTE: This key is not found on all the systems.
  6. In the right pane, delete the value:

    chile c:\windows\detection.exe
  7. Exit the Registry Editor.



Writeup By: Kaoru Hayashi