W32.Mugly.B@mm

Printer Friendly Page

Discovered: November 30, 2004
Updated: February 13, 2007 12:30:36 PM
Also Known As: Win32.Mugly.B [Computer Associ, Email-Worm.Win32.Wurmark.a [Ka, W32/Mugly.b@MM [McAfee], W32/Wurmark-A [Sophos]
Type: Worm
Systems Affected: Windows



W32.Mugly.B@mm is a worm that uses its own SMTP engine to spread by sending itself as an email attachment to addresses gathered from the infected computer. It also drops and runs a W32.Spybot.Worm variant, and may attempt to open a back door on the infected computer.


W32.Mugly.B@mm is a repacked variant of W32.Mugly.A@mm .

Antivirus Protection Dates

  • Initial Rapid Release version December 01, 2004
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version December 01, 2004
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date December 01, 2004

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

Writeup By: Yana Liu

Discovered: November 30, 2004
Updated: February 13, 2007 12:30:36 PM
Also Known As: Win32.Mugly.B [Computer Associ, Email-Worm.Win32.Wurmark.a [Ka, W32/Mugly.b@MM [McAfee], W32/Wurmark-A [Sophos]
Type: Worm
Systems Affected: Windows


When W32.Mugly.B@mm is executed it performs the following actions:

  1. Copies itself as %System%\xxz.tmp.

    Note: %System% is a variable that refers to the System folder. By default this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).

  2. Creates the following files:
    • %System%\ attached.zip (zipped copy of worm)
    • %System%\ winit.exe (attributes are set to read_only, hidden, and system. This is a variant of W32.Spybot.Worm.)
    • %System%\ uglym.jpg
    • %System%\ ANSMTP.DLL (valid ActiveX email engine)
    • %System%\ bszip.dll (valid archive engine)
    • %System%\ SVKP.sys (not viral)

  3. Opens a browser window to display the file uglym.jpg.



  4. Searches for email addresses in files with the following extensions:
    • .wab
    • .adb
    • .tbb
    • .dbx
    • .asp
    • .php
    • .htm
    • .html
    • .sht
    • .txt
    • .doc

      Avoids addresses that contain any of the following strings:
    • adaware
    • nod32
    • trendmicro
    • avguk
    • grisoft
    • pandasoftware
    • sophos
    • .gov
    • symantec
    • lavasoft
    • mcafee
    • kaspersky

  5. Sends itself to the email addresses found on the computer, using its own SMTP engine (contained in the file ANSMTP.DLL).

  6. Creates the following registry entries:

    HKEY_CLASSES_ROOT\ANSMTP.MassSender
    HKEY_CLASSES_ROOT\ANSMTP.MassSender.1
    HKEY_CLASSES_ROOT\ANSMTP.OBJ
    HKEY_CLASSES_ROOT\ANSMTP.OBJ.1
    HKEY_CLASSES_ROOT\CLSID\{253664FB-EDFC-4AC6-BD69-B322F466AEED}
    HKEY_CLASSES_ROOT\CLSID\{887A577B-406B-48FF-80CB-70752BFCD7B4}
    HKEY_CLASSES_ROOT\TypeLib\{DE6317F7-6EF0-45C2-88D1-8E09415817F1}
    HKEY_CLASSES_ROOT\Interface\{68B8DCDB-EFA4-420A-BB8A-71B9892A2063}
    HKEY_CLASSES_ROOT\Interface\{1E98666F-6260-42C9-B846-32B20FDEFE7B}
    HKEY_CLASSES_ROOT\Interface\{A5F6C90C-ABE4-4C57-A421-8C5A202AA9F8}
    HKEY_CLASSES_ROOT\Interface\{B13281CF-8778-4C98-AE23ABBA4637A33D}

    to register its own SMTP engine (contained in the file ANSMTP.DLL).

  7. Sends itself as an email attachment to addresses found on the infected computer, using its own SMTP engine. The email has the following characteristics:

    From: (Spoofed)

    Subject: (One of the following)
    • Hhahahah lol!!!!
    • Your Pic On A Website!!
    • Rate My Pic.......
    • You have an Admirer

      Message body: (One of the following)
    • i found this on my computer from ages ago
      download it and see if you can remember it
      lol i was lauging like mad when i saw it! :D
      email me back haha...
    • I was looking at a website and came across
      this pic they look just like you! infact im sure
      is it someonce else :S ? Ive Added the pic in
      a zip so download it and check & email me back!
    • Hi ive sent 5 emails now and nobody will rate
      my pic!! :( please download and tell me what you
      think out of 10 , dont worry if you dont like it
      just say i wont be offended p.s i was drunk when
      it was taken :P
    • Someone has asked us on there behalf to send
      you this email and tell you they think you are
      wonderfull!!! All the The mystery persons details
      you need are enclosed in the attachment :)
      please download and respond telling us if you
      would like to make further contact with this
      person.
      Regards Hallmark Admirer Mail Admin.

      The message body may also include the following:
    •   _____  
      Current email was sent by an Evaluation License.
      Note: This footer will be removed with Licensed Version


      Attachment: attachment.zip

      Where attachment.zip contains one of the following files:
    • Pic_001.exe
    • Photo_01.pif
    • admire_001.exe
    • is_this_you.scr
    • love_04.scr
    • for_you.pif
    • Scan_04.scr
    • Sexy_09.scr

  8. Drops and executes the file winit.exe, which is a variant of W32.Spybot.Worm. When winit.exe is executed it performs the next steps.

  9. Adds the value:

    "virtual"="winit.exe"

    to the following registry keys:

    HKEY_CURRENT_USER\Software\Microsoft\OLE
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
    RunServices

    so that the worm runs when Windows starts.

  10. Adds the value:

    "EnableDCOM"="N"

    to the registry key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\OLE

    to disable DCOM.

  11. Creates the following registry entry:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SVKP

    to create a service, and the corresponding key:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root\SVKP

  12. Opens a back door by connecting to windowss.serveftp.com and joining a specific channel. Listens for commands from a remote attacker.

  13. Copies itself to the following network shares, which are protected with weak passwords:
      • ADMIN$
      • IPC$
      • C$
      • D$

  14. May attempt to spread by exploiting the following vulnerabilities:


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: Yana Liu

Discovered: November 30, 2004
Updated: February 13, 2007 12:30:36 PM
Also Known As: Win32.Mugly.B [Computer Associ, Email-Worm.Win32.Wurmark.a [Ka, W32/Mugly.b@MM [McAfee], W32/Wurmark-A [Sophos]
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. Disable System Restore (Windows Me/XP).
  2. Update the virus definitions.
  3. Run a full system scan and delete all the files detected as W32.Mugly.B@mm.
  4. Delete the value that was added to the registry.
  5. Delete files created by the threat.
For specific details on each of these steps, read the following instructions.

1. To disable 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:
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.

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. To update 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 daily. 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. To scan for and delete 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.Mugly.B@mm, click Delete.

    Note:
    If your Symantec antivirus product reports that it cannot delete an infected file, Windows may be using the file. To fix this, run the scan in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode." Once you have restarted in Safe mode, run the scan again.

    (After the files are deleted, you can leave the computer in Safe mode and proceed with section 4. When that is done, restart the computer in Normal mode.)

4. To delete the value from the registry
Important: 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.
  1. Click Start > Run.
  2. Type regedit

    Then click OK.

  3. Navigate to the key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

  4. In the right pane, delete the value:

    "virtual"="winit.exe"

  5. Navigate to the key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
    RunServices

  6. In the right pane, delete the value:

    "virtual"="winit.exe"

  7. Navigate to the key:

    HKEY_CURRENT_USER\Software\Microsoft\OLE

  8. In the right pane, delete the value:

    "virtual"="winit.exe"

  9. Navigate to and delete the following registry keys:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SVKP
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root\SVKP

  10. If you are not using ANSMTP, navigate to and delete the following registry entries:

    HKEY_CLASSES_ROOT\ANSMTP.MassSender
    HKEY_CLASSES_ROOT\ANSMTP.MassSender.1
    HKEY_CLASSES_ROOT\ANSMTP.OBJ
    HKEY_CLASSES_ROOT\ANSMTP.OBJ.1
    HKEY_CLASSES_ROOT\CLSID\{253664FB-EDFC-4AC6-BD69-B322F466AEED}
    HKEY_CLASSES_ROOT\CLSID\{887A577B-406B-48FF-80CB-70752BFCD7B4}
    HKEY_CLASSES_ROOT\TypeLib\{DE6317F7-6EF0-45C2-88D1-8E09415817F1}
    HKEY_CLASSES_ROOT\Interface\{68B8DCDB-EFA4-420A-BB8A-71B9892A2063}
    HKEY_CLASSES_ROOT\Interface\{1E98666F-6260-42C9-B846-32B20FDEFE7B}
    HKEY_CLASSES_ROOT\Interface\{A5F6C90C-ABE4-4C57-A421-8C5A202AA9F8}
    HKEY_CLASSES_ROOT\Interface\{B13281CF-8778-4C98-AE23ABBA4637A33D}

  11. Navigate to and reset the registry key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\OLE\"EnableDCOM"="N"

    to the value:

    "EnableDCOM"="Y"

  12. Exit the Registry Editor.

5. To delete files created by the threat
Navigate to and delete the following files:
    • %System%\uglym.jpg
    • %System%\ANSMTP.DLL (valid ActiveX email engine)
    • %System%\bszip.dll (valid archive engine)
    • %System%\SVKP.sys (not viral)


Writeup By: Yana Liu