W32.Ronoper.B@mm

SUMMARY

W32.Ronoper.B@mm is a mass-mailing worm that attempts to spread itself through email, mIRC, and across file-sharing networks. The worm also contains a Backdoor functionality and attempts to terminate the processes of various programs, including antivirus and security software.

The email messages will have the following characteristics:
Subject: Re:
Attachment: melda.scr

W32.Ronoper.B@mm is written in the Borland Delphi programming language and is compressed with UPX.

NOTE: Definitions dated prior to July 6, 2003 will detect this threat as W32.HLLW.Aldem@mm.

Protection

• Virus Definitions (LiveUpdate™ Weekly) June 11, 2003
• Virus Definitions (Intelligent Updater) June 11, 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
• Large Scale E-mailing: Sends itself to all the contacts in the Outlook Address Book.
• Compromises Security Settings: Allows unauthorized remote access to an infected computer. Attempts to terminate the processes of various programs including antivirus and security software.

Distribution

• Distribution Level: High
• Subject of Email: Re:
• Name of Attachment: Melda.scr
• Size of Attachment: 39,936 bytes
• Shared Drives: Spreads through the file-sharing networks.

TECHNICAL DETAILS

When W32.Ronoper.B@mm runs, it does the following:

1. Copies itself to the %Windir% folder as the following files:
   • Systools.exe
   • Melda.scr
     
     
2. Adds the value:
   
   "System Toolkit" = "%windir%Systools.exe"
   
   to the registry keys:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersion
   RunServices
   
   
3. Overwrites or creates the following keys and values:
   
   HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersion
   PoliciesSystem
   "NoDispCPL"=DWORD:1
   "DisableRegistryTools"=DWORD:1
   
   HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersion
   ExplorerAdvanced
   "Hidden"=DWORD:1
   
   
4. Disables some programs by terminating the active processes and stopping the active services. The worm terminates the following processes:
   • _Avpcc.exe
   • _avpm.exe
   • Ackwin32.exe
   • Anti-trojan.exe
   • Apvxdwin.exe
   • Autodown.exe
   • Avconsol.exe
   • Ave32.exe
   • Avgctrl.exe
   • Avkserv.exe
   • Avnt.exe
   • Avp.exe
   • Avp32.exe
   • Avpcc.exe
   • Avpdos32.exe
   • Avpm.exe
   • Avptc32.exe
   • Avpupd.exe
   • Avsched32.exe
   • Avwin95.exe
   • Avwupd32.exe
   • Blackd.exe
   • Blackice.exe
   • Cfiadmin.exe
   • Cfiaudit.exe
   • Cfinet.exe
   • Cfinet32.exe
   • Claw95.exe
   • Claw95cf.exe
   • Cleaner.exe
   • Cleaner3.exe
   • Dvp95.exe
   • Dvp95_0.exe
   • Ecengine.exe
   • Esafe.exe
   • Espwatch.exe
   • F-agnt95.exe
   • Findviru.exe
   • Fprot.exe
   • F-prot.exe
   • F-prot95.exe
   • Fp-win.exe
   • Frw.exe
   • F-stopw.exe
   • Iamapp.exe
   • Iamserv.exe
   • Ibmasn.exe
   • Ibmavsp.exe
   • Icload95.exe
   • Icloadnt.exe
   • Icmon.exe
   • Icsupp95.exe
   • Icsuppnt.exe
   • Iface.exe
   • Iomon98.exe
   • Jedi.exe
   • Lockdown2000.exe
   • Lookout.exe
   • Luall.exe
   • Moolive.exe
   • Mpftray.exe
   • N32scanw.exe
   • Navapw32.exe
   • Navlu32.exe
   • Navnt.exe
   • Navw32.exe
   • Navwnt.exe
   • Nisum.exe
   • Nmain.exe
   • Normist.exe
   • Nupgrade.exe
   • Nvc95.exe
   • Outpost.exe
   • Padmin.exe
   • Pavcl.exe
   • Pavsched.exe
   • Pavw.exe
   • Pccwin98.exe
   • Pcfwallicon.exe
   • Persfw.exe
   • Rav7.exe
   • Rav7win.exe
   • Regedit.exe
   • Rescue.exe
   • Safeweb.exe
   • Scan32.exe
   • Scan95.exe
   • Scanpm.exe
   • Scrscan.exe
   • Serv95.exe
   • Smc.exe
   • Sphinx.exe
   • Sweep95.exe
   • Tbscan.exe
   • Tca.exe
   • Tds2-98.exe
   • Tds2-nt.exe
   • Vet95.exe
   • Vettray.exe
   • Vscan40.exe
   • Vsecomr.exe
   • Vshwin32.exe
   • Vsstat.exe
   • Webscanx.exe
   • Wfindv32.exe
   • Zonealarm.exe
     
     
5. Uses MAPI to email itself to all the contacts in the Windows Address Book. The email has the following characteristics:
   
   Subject: Re:
   Body: Look at The Attachments for Secret Pictures of My Girl Friend..
   Attachment: melda.scr
   
   
6. Copies itself to the KaZaA download folder as:
   • Norton Antivirus 2003 Professional Edition.exe
   • Systools.exe
   • Norton Internet Security 2003 Professional.exe
   • Windows XP Key Generator.exe
   • Windows XP Keygen.exe
   • Icq Hack.exe
   • Hotmail Hack.exe
   • Spy Cam - Girl Masterbating.scr
   • PornStar in Hardcore Action.scr
   • WarCraft 3 Battle.net Key Generator.exe
   • WarCraft 3 MapHack.exe
   • StarCraft Battle.net Keygen.exe
   • StarCraft Maphack.exe
   • HardCore Action In The School.scr
   • HardCore - College Webcam.scr
   • Penis Enlargement Secrets.scr
     
     
7. Creates the mIRC script, %Windir%SysScript.exe, to allow the worm to spread using mIRC.

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

These 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.Ronoper.B@mm.
3. Reverse the changes that the worm made to the registry.

For specific details on each of these procedures, 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 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.

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.Ronoper.B@mm, click Delete.

3. Reversing the changes made to the registry

Copying Regedit.exe to Regedit.com and editing the registry
Because the worm modified the registry so that you cannot run the .exe files, first make a copy of the Registry Editor as a file with the .com extension, and then run the file.

1. Do one of the following, depending on the version of Windows you are running:
   • Windows 95/98 users:
     1. Click Start.
     2. Point to Programs.
     3. Click the MS-DOS Prompt. (A DOS window opens at the C:Windows prompt.) Proceed to step b of this section.
   • Windows Me users:
     1. Click Start.
     2. Point to Programs.
     3. Point to Accessories.
     4. Click the MS-DOS Prompt. (A DOS window opens at the C:Windows prompt.) Proceed to step b of this section.
   • Windows NT/2000 users:
     1. Click Start, and then click Run.
     2. Type command, and then press Enter. (A DOS window opens.)
     3. Type cd winnt, and then press Enter.
     4. Go to step 2 of this section.
   • Windows XP users:
     1. Click Start, and then click Run.
     2. Type command, and then press Enter. (A DOS window opens.)
     3. Type the following:
        
        cd
        cd windows
        
        Press Enter after typing each one.
        
     4. Proceed to step b of this section.
        
        
2. Type copy regedit.exe regedit.com
   
   and then press Enter.
   
3. Type start regedit.com
   
   and then press Enter. (The Registry Editor opens in front of the DOS window.)
   
   After you finish editing the registry, exit the Registry Editor, and then exit the DOS window as well.
   
4. 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. For instructions, read the document, "How to make a backup of the Windows registry."
   
5. Navigate to the keys:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersion
   RunServices
   
   
6. In the right pane, delete the value: "System Toolkit"
   
7. Exit the Registry Editor.