W32.HLLW.Reckus

SUMMARY

W32.HLLW.Reckus is a worm that spreads through peer-to-peer file-sharing networks, such as KaZaA, Morpheus, and WinMX. It overwrites Notepad.exe and Regedit.exe with copies of itself and terminates antivirus and firewall processes.

The existence of C:WindowsLOL.exe is a sign of possible infection.

This worm is written in Delphi and is packed with UPX.

Protection

• Virus Definitions (LiveUpdate™ Weekly) October 29, 2003
• Virus Definitions (Intelligent Updater) October 27, 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
• Deletes Files: Overwrites C:WindowsNotepad.exe and C:WindowsRegedit.exe; may delete other system files.
• Modifies Files: Modifies configuration files for IRC clients.
• Compromises Security Settings: Terminates antivirus and firewall processes.

Distribution

• Distribution Level: Medium
• Shared Drives: Creates C:WindowsSystem32Shared as a shared KaZaA folder.
• Target of Infection: KaZaA file-sharing network.

TECHNICAL DETAILS

When W32.HLLW.Reckus is executed, it performs the following actions:

1. Copies itself to the following hard-coded locations as the following files:
   
   • C:Windows
     • LOL.exe
     • Notepad.exe
     • Regedit.exe
       
       

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       Note: The worm overwrites the legitimate applications, Notepad and Regedit, if they are found in this location.

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   • C:WindowsSystem32
     • Progman.exe
     • Shutdown32.exe
     • Userinit.exe
     • Winsys32.exe
       
       
   • C:WindowsSystem32Shared, C:Program FilesWinMXMy Shared Folder, and C:My Downloads
     • Alcohol 120 keygen.exe
     • Battlefield 1942 keygen.exe
     • BlackICE PC Protection 3.5 keygen.exe
     • BlindWrite crack (all versions).exe
     • Briana Banks (screensaver).exe
     • Britney spears DressUp Doll.exe
     • Britney Spears NUDE (screensaver).exe
     • Carmen Electra NUDE (screensaver).exe
     • DC++ ShareFaker.exe
     • Delphi 7 Enterprise keygen.exe
     • Dransik character editor.exe
     • Dransik classic account unlocker.exe
     • Everquest 2 NoCD crack.exe
     • GTA Vice City Universal NoCD patch.exe
     • Half-Life keygen.exe
     • Imesh No-Adverts.exe
     • Jedi Academy keygen.exe
     • KAV Personal Pro crack & keygen.exe
     • Kazaa AD-remover.exe
     • Kazaa Speedup 3.05.exe
     • KMD 2.1.exe
     • Krystal Steel (screensaver).exe
     • Lavasoft Ad-Aware 6 keygen.exe
     • Lavasoft Ad-aware 6 pro keygen.exe
     • Matrix Code Emulator Screensaver.exe
     • Microsoft Visual C++ keygen.exe
     • Mirc 6.03 serial generator.exe
     • MusicMatch JukeBox 8.0 keygen.exe
     • Nero Burning Rom (5.X + 6.X) keygen.exe
     • Norton Anti-Virus 2003 crack.exe
     • Norton Anti-Virus 2003 keygen.exe
     • Norton Anti-Virus 2004 crack.exe
     • Norton Anti-Virus 2004 keygen.exe
     • Norton Internet Security crack.exe
     • Office XP keygen.exe
     • Panda Anti-Virus Titanium keygen.exe
     • Playstation 2 emulator.exe
     • PopUp Killer crack (all versions).exe
     • Retina vulnerability scan keygen.exe
     • Runescape character editor.exe
     • Sophie Sweet (screensaver).exe
     • Tawny Roberts (screensaver).exe
     • Tiny Personal Firewall 5.0 crack.exe
     • UT 2003 keygen.exe
     • Vietcong keygen.exe
     • Visual Basic 6 keygen.exe
     • Visual Studio keygen.exe
     • Warcraft III Reign Of Chaos 1.0X Virtual Crack.exe
     • Window Washer 4.8 keygen.exe
     • Windows XP activation crack.exe
     • WinRAR keygen (all versions).exe
     • WinZip keygen (all versions).exe
       
       

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       Note: C:Windows, C:WindowsSystem32, and C:WindowsSystem32Shared are created if they do not already exist.

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2. Creates the following non-viral files in C:Windows:
   • Winbfkey.txt
   • Winhelp.txt
   • Winkey.txt
   • Winutkey.txt
     
     
3. Adds the value:
   
   "WinSys32"="C:Windowssystem32Winsys32.exe"
   
   to the registry key:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
   so that the worm runs when you start Windows.
   
   
4. Creates a script.ini file in the following folders, if they exist:
   • C:Program FilesmIRC
   • C:Program FilesNoNameScript
   • C:Scoop2003
   • C:Program FilesFinnishIRC XP
   • C:Sentinel4
   • C:Program FilesGamers.IRC
   • C:evolution
   • C:mIRC
     
     The script contains commands that will automatically send messages to other IRC users. The messages consist of links to various Web sites, some of which may contain malicious code.
     
     
5. Attempts to steal CD keys for various games.
   
   
6. Deletes the following files, if they exist:
   • C:WindowsCmd.exe
   • C:WindowsSystem32Taskman.exe
   • C:WindowsSystem32Taskmgr.exe
   • C:WindowsSystem32Regedt32.exe
   • C:WindowsSystem32Regsvr32.exe
   • C:WindowsSystem32Autochk.exe
   • C:WindowsSystem32Chkntfs.exe
   • C:WindowsSystem32Chkdsk.exe
   • C:WindowsSystem32Shutdown.exe
     
     
7. Changes the Internet Explorer home page to point to a pornographic Web site.
   
   
8. Enters an infinite loop. Every 10 seconds, the worm terminates antivirus and firewall processes, and re-copies itself as C:WindowsSystem32Winsys32.exe.

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.

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Note: If W32.HLLW.Reckus has already run, it is possible that you will no longer be able to start Windows. The damage that W32.HLLW.Reckus does will vary with both the operating system and the installation path.

Even if you can start Windows, once it has run, you may no longer be able to edit the registry as required to remove the changes made to the registry files.

In this situation, you must replace the deleted files and the Windows Registry Editor, either from a clean backup or by re-installing the operating system.

Once you have restored the deleted or overwritten system files, follow all the removal instructions.

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1. Disable System Restore (Windows Me/XP).
2. Update the virus definitions.
3. Do one of the following:
   • Windows 95/98/Me: Restart the computer in Safe mode.
   • Windows NT/2000/XP: End the Trojan process.
4. Run a full system scan and delete all the files detected as W32.HLLW.Reckus.
5. Reverse the changes that the Trojan made to the registry.
   

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

1. Disabling System Restore (Windows Me/XP)
If you are running Windows Me or Windows XP, we recommend that you temporarily turn off System Restore. Windows Me/XP uses this feature, which is enabled by default, to restore the files on your computer in case they become damaged. If a virus, worm, or Trojan infects a computer, System Restore may back up the virus, worm, or Trojan on the computer.

Windows prevents outside programs, including antivirus programs, from modifying System Restore. Therefore, antivirus programs or tools cannot remove threats in the System Restore folder. As a result, System Restore has the potential of restoring an infected file on your computer, even after you have cleaned the infected files from all the other locations.

Also, a virus scan may detect a threat in the System Restore folder even though you have removed the threat.

For instructions on how to turn off System Restore, read your Windows documentation, or one of the following articles:

• "How to disable or enable Windows Me System Restore"
• "How to turn off or turn on Windows XP System Restore"
  

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Note: When you are completely finished with the removal procedure and are satisfied that the threat has been removed, re-enable System Restore by following the instructions in the aforementioned documents.

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

2. 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 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).
• 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).
  
  The Intelligent Updater virus definitions are available: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.

3. Restarting the computer in Safe mode or ending the Trojan process

Windows 95/98/Me
Restart the computer in Safe mode. All the Windows 32-bit operating systems, except for Windows NT, can be restarted in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."

Windows NT/2000/XP
To end the Trojan process:
1. Press Ctrl+Alt+Delete once.
2. Click Task Manager.
3. Click the Processes tab.
4. Double-click the Image Name column header to alphabetically sort the processes.
5. Scroll through the list and look for WinSys32.exe.
6. If you find the file, click it, and then click End Process.
7. Exit the Task Manager.
   

4. 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.Reckus, click Delete.

5. Reversing the changes made to the registry

NOTE: Because this worm overwrites regedit.exe, it will be necessary to restore this file from a backup copy before performing this step.

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WARNING: Symantec strongly recommends that you back up the registry before making 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.

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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 value:
   
   "WinSys"="C:Windowssystem32Winsys32.exe""
   
   
5. Exit the Registry Editor.