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Discovered: December 11, 2007
Updated: December 11, 2007 4:40:31 PM
Type: Worm
Infection Length: exe:14,4896 bytes ; dll:88,000 bytes
Systems Affected: Windows

W32.Mubla.C@mm is a mass-mailing worm that spreads through email and MSN Messenger. It also opens a back door on the compromised computer.

Antivirus Protection Dates

  • Initial Rapid Release version December 11, 2007 revision 007
  • Latest Rapid Release version August 08, 2016 revision 023
  • Initial Daily Certified version December 11, 2007 revision 021
  • Latest Daily Certified version August 09, 2016 revision 001
  • Initial Weekly Certified release date December 12, 2007

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

Writeup By: Tomasz Smolarek

Discovered: December 11, 2007
Updated: December 11, 2007 4:40:31 PM
Type: Worm
Infection Length: exe:14,4896 bytes ; dll:88,000 bytes
Systems Affected: Windows

When the worm is executed, it creates the following files:

  • %System%\msnmsgr.exe
  • %System%\syslinks2.dll

Next, it creates the following registry entries so that it executes whenever Windows starts:
  • HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{F5A64829-96E4-4296-B9DC-A3D20DD885F5}\"InProcServer32" = "syslinks2.dll"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ShellServiceObjectDelayLoad\"Version3" = "{F5A64829-96E4-4296-B9DC-A3D20DD885F5}"

It injects the following file into explorer.exe and to all running processes:

Next, the worm connects to #.bb IRC channel on the www.brendashop.com domain on TCP port 80 and opens a back door, allowing an attacker to perform the following actions:
  • Download files
  • Steal passwords

The worm searches for email addresses in Windows Address Book and in files that contain the following extensions:
  • txt
  • htm
  • sht
  • jsp
  • cgi
  • xml
  • php
  • asp
  • dbx
  • tbb
  • adb
  • pl
  • html
  • wab

It performs a search in the following locations:
  • %WinDir%
  • %UserProfiles%\Local Settings\Temporary Internet Files\
  • All fixed drives from A to Z

The worm spreads through MSN Messenger. It uses the following instant message texts:
  • hihi look at my horny pictures :$
  • hi howdy ? accept it !! (H)
  • look at my great summer pictures (B)(D)
  • i love u thats why i send this !!! :o
  • oh my god look at this picture :o wowwww
  • this is me drinking some juice !!
  • bak sana Paris Hilton ne hale gelmis hapiste :(
  • Sen ve Ben !!! .... BAK :p
  • Baksana benim fotograflara hihi :p
  • Hey benim fotolarimi kabul et :o !!
  • Iyi arkadasimla fotorafdayim :$ !!
  • benim bu ciplak fotoda :o ama baskasina yollama
  • bak ne buldum :o Jessica alba ciplak !!
  • hey regarde mes nouvelles tofs :P
  • salut! accept mes tofs! (H)
  • T'as pas vu mes tof d'été ?? (B)(D)
  • hey je viens de trouvé tes tof sur net :S
  • oh mon dieux regarde ca!!
  • c moi entrain du boire jus!!
  • ma soeur voulait que tu regarde ces tof... :P
  • hihi kijk eens naar mijn geile fotos :$
  • hihi
  • foto in spanje check it (H)
  • ik hou van je, daarom stuur ik je dit !!! :o
  • fotos van executie van pim van tuin, deze zijn nog nooit eerder vertoont bekijk ze !!
  • hier ga ik volgendjaar naartoe op vakantie!!(B)
  • guck wie scheisse Paris Hilton aussieht, seitdem sie wieder aus dem knast ist :(
  • du und ich !!! ....guck :p
  • siehe meine fotos hihi :p
  • hey bitte nimm meine fotos an :o !!
  • ein foto mit meinem besten freund und mir :$ !!
  • das bin ich total nackt :o bitte sende es niemand anderem
  • \x8A\x8F\x9D\xCE\x8C\x87\x80\xCE\x87\x8D\x86\xCE\x9A\x81\x9A\x8F\x82\xCE\x80\
  • Guarda come Paris Hilton sprecato è, dopo che era imprijonata :(
  • Tu ed io !!! .... guarda :p
  • Guardi le mie foto hihi :p
  • Mairee photos accept karo :o !!
  • Una foto con me ed il mio amico migliore :$ !!
  • Questa e me totaly nudo :o prego non trasmette a chiunque
  • Osservi che cosa ho trovato sul internet :o Jessica alba NUDA !!
  • Veja como Paris Hilton está acabada depois de ter sido presa :(
  • Você e eu !!!! .... Veja :p
  • Veja as minhas fotos hehehe :p
  • Por favor aceite as minhas fotos :o !!
  • Uma foto com o meu melhor amigo e eu :$ !!
  • Esta sou eu totalmente nua :o por favor não mande isso pra ninguém
  • :o Jessica Alba NUA !!
  • NI HE WO !!! .... QING KAN :p
  • C'est moi totalement nu :o s'il te plait ne l'envoie a personne d'autre
  • Kolla hur förstörd Paris Hilton är, efter att hon fängslades :(
  • Du och jag !! .... Kolla ;)
  • Kolla på min bilder, hihi :p
  • Hey, acceptera mina bilder, snälla :o
  • En bild på mig och min bästa vän :$ !!!
  • Detta är jag HELT naken.. :o Skicka inte till någon annan, snälla...
  • Kolla vad jag hittade på nätet :o Jessica Alba NAKEN !!
  • Mira cómo Paris Hilton es perdida después de ser encarcelada :(
  • Usted e yo !!! .... Mira :p
  • Mira mis fotos jejeje :p
  • Ha aceptado mis fotos por favor :o !!
  • Una foto con mi mejor amigo e yo :$ !!
  • Esta soy yo totalmente desnuda :o por favor no envía para nadie
  • Mira lo que encontré en la WEB :o Jessica Alba DESNUDA !!
  • Lede hvor spild Paris Hilton er efter hun fik fængsel :(
  • Jer og Mig !!! ... se :p
  • Se på min fotos :p
  • Hej behage optage min foto :o !!
  • EN foto hos mig og min bedst ven :$ !!
  • denne er mig hele bar behage vage vendlig og sende den ikk til nogle :o
  • Lede hvad jeg fandt oven på den net :o Jessica Alba bar !!

The threat also spreads by sending itself as an email attachment. It uses its own SMTP engine to send messages to gathered email addresses. The email may have the following characteristics:

One of the following:
  • samples@[SPOOFED DOMAIN]
  • postmaster@[SPOOFED DOMAIN]
  • webmaster@[SPOOFED DOMAIN]
  • noone@[SPOOFED DOMAIN]
  • nobody@[SPOOFED DOMAIN]
  • nothing@[SPOOFED DOMAIN]
  • anyone@[SPOOFED DOMAIN]
  • someone@[SPOOFED DOMAIN]
  • rating@[SPOOFED DOMAIN]
  • contact@[SPOOFED DOMAIN]
  • somebody@[SPOOFED DOMAIN]
  • privacy@[SPOOFED DOMAIN]
  • service@[SPOOFED DOMAIN]
  • submit@[SPOOFED DOMAIN]
  • admin@[SPOOFED DOMAIN]
  • crosoft@[SPOOFED DOMAIN]
  • support@[SPOOFED DOMAIN]
  • ntivi@[SPOOFED DOMAIN]
  • linux@[SPOOFED DOMAIN]
  • listserv@[SPOOFED DOMAIN]
  • certific@[SPOOFED DOMAIN]
  • google@[SPOOFED DOMAIN]
  • accoun@[SPOOFED DOMAIN]
  • secur@[SPOOFED DOMAIN]
  • abuse@[SPOOFED DOMAIN]



One of the following:
  • Account Error ID#5203
  • Your Membership Details!
  • Sorry your account has been suspended
  • You've received an E-Card from a dear friend.
  • Free one year trial
  • Your account has been suspended for over usage
  • Visa and Mastercard and Amex news
  • Security Notice


One of the following:
  • Please use the following password the read the attachment
  • The message cannot be represented in plain text because it contains personal and sensitive data, so the message has been attached.Please use the following password the read the attachment
  • The message cannot be represented in 7-bit ASCII because it contains personal and sensitive data, so has been sent as a passworded attachment.Please use the following password the read the attachment
  • The message has been sent as a secure passworded attachment.Please use the following password the read the attachment
  • Partial message is available as a secure passworded attachment.Please use the following password the read the attachment

Followed by:
Password: %s


One of the following:
  • INFO.zip
  • Details.zip
  • Secure_Details.zip

The above attachment is a password protected zip archive that contains a file which is a copy of the worm.

The file contains one of the following extensions:
  • scr
  • pif
  • exe


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: Tomasz Smolarek

Discovered: December 11, 2007
Updated: December 11, 2007 4:40:31 PM
Type: Worm
Infection Length: exe:14,4896 bytes ; dll:88,000 bytes
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.
  4. Delete any values added to the registry.

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, reenable 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.

    If you use Norton AntiVirus 2006, Symantec AntiVirus Corporate Edition 10.0, or newer products, LiveUpdate definitions are updated daily. These products include newer technology.

    If you use Norton AntiVirus 2005, Symantec AntiVirus Corporate Edition 9.0, or earlier products, LiveUpdate definitions are updated weekly. The exception is major outbreaks, when definitions are updated more often.

  • 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.

The latest Intelligent Updater virus definitions can be obtained here: Intelligent Updater virus definitions . For detailed instructions read the document: How to update virus definition files using the Intelligent Updater .

3. To run a full system scan
  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, follow the instructions displayed by your antivirus program.
Important: If you are unable to start your Symantec antivirus product or the product reports that it cannot delete a detected file, you may need to stop the risk from running in order to remove it. To do 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, restart the computer in Normal mode and proceed with the next section.

Warning messages may be displayed when the computer is restarted, since the threat may not be fully removed at this point. You can ignore these messages and click OK. These messages will not appear when the computer is restarted after the removal instructions have been fully completed. The messages displayed may be similar to the following:

Title: [FILE PATH]
Message body: Windows cannot find [FILE NAME]. Make sure you typed the name correctly, and then try again. To search for a file, click the Start button, and then click Search.

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 subkeys only. For instructions refer to the document: How to make a backup of the Windows registry .
  1. Click Start > Run.
  2. Type regedit
  3. Click OK.

    Note: If the registry editor fails to open the threat may have modified the registry to prevent access to the registry editor. Security Response has developed a tool to resolve this problem. Download and run this tool, and then continue with the removal.

  4. Navigate to and delete the following registry entries:

    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{F5A64829-96E4-4296-B9DC-A3D20DD885F5}\"InProcServer32" = "syslinks2.dll"
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ShellServiceObjectDelayLoad\"Version3" = "{F5A64829-96E4-4296-B9DC-A3D20DD885F5}"

  5. Exit the Registry Editor.

    Note: If the risk creates or modifies registry subkeys or entries under HKEY_CURRENT_USER, it is possible that it created them for every user on the compromised computer. To ensure that all registry subkeys or entries are removed or restored, log on using each user account and check for any HKEY_CURRENT_USER items listed above.

Writeup By: Tomasz Smolarek