Discovered: October 24, 2003
Updated: February 13, 2007 12:12:34 PM
Also Known As: W32/Sober@MM [McAfee], I-Worm.Sober [Kaspersky], W32/Sober-A [Sophos], WORM_SOBER.A [Trend]. Sober [F, W32/Sober.A@mm [Frisk], W32/Sober.A [Norman], Win32/Sober.A [Eset], Win32.Sober.A [Computer Associ
Type: Worm
Systems Affected: Windows


W32.Sober@mm is a mass-mailing worm that uses its own SMTP engine to spread itself. The subject of the email varies, and it will be in either English or German.

The name of the email attachment varies, and it will have a .bat, .com, .exe, .pif, or .scr file extension.

This threat is written in the Microsoft Visual Basic programming language and is compressed with UPX.

When W32.Sober@mm is first run, it may display the fake error message "File not complete!"


Note: Virus definitions dated October 24, 2003, revision 20 and greater, will detect this threat.


Symantec Security Response has developed a removal tool to clean the infections of W32.Sober@mm.


Antivirus Protection Dates

  • Initial Rapid Release version October 24, 2003
  • Latest Rapid Release version August 08, 2016 revision 023
  • Initial Daily Certified version October 24, 2003
  • Latest Daily Certified version August 09, 2016 revision 001
  • Initial Weekly Certified release date October 24, 2003

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

Writeup By: Yana Liu

Discovered: October 24, 2003
Updated: February 13, 2007 12:12:34 PM
Also Known As: W32/Sober@MM [McAfee], I-Worm.Sober [Kaspersky], W32/Sober-A [Sophos], WORM_SOBER.A [Trend]. Sober [F, W32/Sober.A@mm [Frisk], W32/Sober.A [Norman], Win32/Sober.A [Eset], Win32.Sober.A [Computer Associ
Type: Worm
Systems Affected: Windows


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

  1. May display this fake message:




  2. Copies itself as %System%\Similare.exe.


    Note: %System% is a variable. The worm locates the System folder and copies itself to that location. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).

  3. Creates several copies of itself to the %System% directory using variable filenames, which may be chosen from the following list:
    • antiv.exe
    • driver.exe
    • driverini.exe
    • drv.exe
    • expoler.exe
    • filexe.exe
    • hlp16.exe
    • lssas.exe
    • qname.exe
    • spoole.exe
    • swchost.exe
    • syshost.exe
    • systemchk.exe
    • systemini.exe
    • winchk.exe
    • winlog32.exe
    • winreg.exe

      Note: The worm may append some garbage data to the end of its copy.

  4. Adds the value that refers to the worm copy in %System% folder to the registry keys:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

    so that the worm runs when you start Windows.

    For example, the worm may add the following value to these registry keys,

    "hostend"="%System%\Winreg.exe"
  5. Creates the file, %System%\Macromed\Help\Media.dll.

  6. Retrieves email addresses from local files and stores them in the Media.dll.file.

  7. Uses its own SMTP engine to send itself to all the email addresses it finds.
      The email subject is one of the following:
    • Neuer Virus im Umlauf!
    • Sie versenden Spam Mails (Virus?)
    • Ein Wurm ist auf Ihrem Computer!
    • Langsam reicht es mir
    • Sie haben mir einen Wurm geschickt!
    • Hi Schnuckel was machst du so ?
    • VORSICHT!!! Neuer Mail Wurm
    • Re: Kontakt
    • RE: Sex
    • Sorry, Ich habe Ihre Mail bekommen
    • Hi Olle, lange niks mehr gehört!
    • Re: lol
    • Viurs blockiert jeden PC (Vorsicht!)
    • Überraschung
    • Ich habe Ihre E-Mail bekommen !
    • Jetzt rate mal, wer ich bin !?
    • Neue Sobig Variante (Lesen!!)
    • Back At The Funny Farm
    • Ich Liebe Dich
    • New internet virus!
    • You send spam mails (Worm?)
    • A worm is on your computer!
    • Now, it's enough
    • You have sent me a virus!
    • Hi darling, what are you doing now?
    • Be careful! New mail worm
    • Re: Contact
    • RE: Sex
    • Sorry, I've become your mail
    • Hey man, long not see you
    • Viurs blocked every PC (Take care!)
    • Surprise
    • I've become your mail!
    • Advise who I am!
    • New Sobig-Worm variation (please read)
    • I love you (I'm not a virus!)
      The attachment is one of the following:

    • AntiVirusDoc.pif
    • Check-Patch.bat
    • Screen_Doku.scr
    • Removal-Tool.exe
    • Perversionen.scr
    • Bild.scr
    • robot_mail.scr
    • RobotMailer.com
    • Privat.exe
    • AntiTrojan.exe
    • Mausi.scr
    • NackiDei.com
    • Anti-Sob.bat
    • security.pif
    • Funny.scr
    • Liebe.com
    • Odin_Worm.exe
    • anti_virusdoc.pif
    • check-patch.bat
    • removal-tool.exe
    • screen_doc.scr
    • potency.pif
    • perversion.scr
    • pic.scr
    • CM-Recover.com
    • playme.exe
    • robot_mailer.pif
    • little-scr.scr
    • love.com
    • nacked.com
    • Hengst.pif
    • schnitzel.exe
    • anti-trojan.exe
    • NAV.pif
    • private.exe
    The email may spoof the From field. For example, it may disguise itself as though it is from UpDate@microsoft.com.

    Here are some email examples:

    Message:
    Ich bekomme ständig von Ihnen Spam Mails mit einem Virus im Gepäck.
    Sie sollten diesen Entfernen!!
    Lesen Sie sich das Dokument durch, bevor Sie meine oder anderen Mailbox sprengen!
    Mit freundlichen Grüßen:
    <an sender>
    Attachment: AntiVirusDoc.pif

    Message:
    Ich bekomme ständig von Ihnen Spam Mails mit einem Virus im Gepäck.
    Sie sollten diesen Entfernen!!
    Wie es aussieht, ist bei Ihnen der ODIN Wurm aktiv!
    Sie sollten mit dem Patch-Programm testen,
    ob der Wurm bei Ihnen auf der Platte ist um Ihn dann automatisch
    löschen zu lasseg
    Niks wie ungut!
    Attachment: Check-Patch.bat

    Message:
    Kaspersky Lab Int. und Norton Anti Virus haben einen neuen Typos von Wurm entdeckt.
    Der Wurm nennt sich selbst ODIN und konnte sich bist jetzt,
    unbemerkt auf vielen Computern ausbreiten!
    Diese Mail wurde selbst mit dem Wurm verschickt, aber, als Anhang mit einem AntiVirus bestückt,
    den Norton in Zusammenarbeit mit Kaspersky Lab entwickelt hat!
    Sie sollten auf jeden Fall das <Removal tool> benutzen um ggf. den Wurm zu entfernen!
    Nachrichten<ID>: <an random number>
    Attachment: Removal-Tool.exe
    Message:
    Kaspersky Lab Int. und Norton Anti Virus haben einen neuen Typos von Wurm entdeckt.
    Der Wurm nennt sich selbst ODIN und konnte sich bist jetzt,
    unbemerkt auf vielen Computern ausbreiten!
    Der Wurm versteckt sich im Bildschirm-Schoner!
    In der -Screen_Doku- Dokumentation lesen Sie, wie Sie den Wurm
    mit wenigen Schritten das Handwerk legen können.
    Robot<Transmission>
    Attachment: Screen_Doku.scr

    Message:
    Ich habe jetzt schon zum
    mal, eine Mail die an Sie
    Adressiert ist bekommen!
    Ähmm... *hust* der Anhang oder besser gesagt, die Dokumentation
    muss Ihnen aber nicht Peinlich sein ! *grins*
    Attachment: Perversionen.scr

    Message:
    Ich habe jetzt schon zum
    mal, eine Mail die an Sie
    Adressiert ist bekommen!
    Oder aber, Sie schicken mir diese Mails ohne es zu Wissen!
    Wenn dies der Fall sein sollte, haben sie wahrscheinlich ein Problem
    mit der COM- Schnittstelle.
    Wie dem auch sei, Ich war so frei und habe Ihnen ein Tool
    mitgeschickt, mit dem Sie die Konsole mal testen können.
    Gruß von:
    Attachment: CM-Recover.com

    Message:
    Habe mir extra einen falschen E-Mail Namen zugelegt um es dir nicht zu leicht zu machen!
    PS:
    War aber nicht meine Idee !
    Darauf kommst DU nie!!!
    Dafür kenne ich Dich zu gut!!
    Löse das kleine Bilderrätsel und ...
    Attachment: Bild.scr

    Message:
    Habe mir extra einen falschen E-Mail Namen zugelegt um es dir nicht zu leicht zu machen!
    PS:
    War aber nicht meine Idee !
    Darauf kommst DU nie!!!
    Dafür kenne ich Dich zu gut!!
    Stell dir einfach vor, das wäre eine Schnitzeljagd und Du bist der Jäger
    Naja, schaffste eh net, im Anhang sind ein paar kleine
    Spielchen, wenn du die Lösen kannst hat du mich, aber ...
    Attachment: schnitzel.exe
    Message:
    Oder liegts daran, dass die mir meine alten Mail Adressen
    weggemacht haben? *grins*
    Naja, Ich will hier nicht über E-Mail die jeder Arsch lesen kann,
    meine privaten Probleme bekannt machen!!
    Ich habe dir mal wat erzählt, naja zu gefährlich über Mail!!
    Steht alles im Anhang,, um den zu entschlüsseln, gebe dein
    Geburtstags-Datum als Passwort ein!
    Attachment: Privat.exe

    Message:
    Oder liegts daran, dass die mir meine alten Mail Adressen
    weggemacht haben? *grins*
    Naja, Ich will hier nicht über E-Mail die jeder Arsch lesen kann,
    meine privaten Probleme bekannt machen!!
    Jedenfalls haben die Schweine mir einen Trojaner auf'm Rechner geknallt!
    Und so isset dann passiert!
    Ich werde mich in den nächsten Tagen noch einmal melden,
    bis dahin solltest du mal deinen Rechner auf Trojaner untersuchen lassen,
    wenn ich einen hatte, hast du 100 pro auch einen!
    Ich habe dir einen guten Trojaner-Sucher mit bei getan!
    OK,... bis dann
    Attachment: AntiTrojan.exe

    Message:
    Programmer of the -Sobig Worm-
    Congratulations!! Your Sobig Worms are very good!!!
    You are a very good programmer!
    Yours faithfully
    Odin alias Anon
    Attachment: Odin_Worm.exe

    Message:
    I permanently get Spam-Mails from you and inside is a virus!!
    You should remove these thing.
    Read the document, before another or my mailbox explode!
    Yours sincerely:
    <sender>
    Attachment: anti_virusdoc.pif

    Message:
    I permanently get Spam-Mails from you and inside is a virus!!
    You should remove these thing.
    Sorry, but the ODIN Worm is probably on your computer!
    You should check this with the patch application.
    See you soon
    Attachment: check-patch.bat

    Message:
    Kaspersky Lab Int. and Norton Anti Virus have found a new typ of worm.
    He calls itself ODIN and he is very variable!
    This mail was spread with this Worm, too. BUT, the attachement is a AntiVirus!!
    Norton and Kaspersky Lab has create this bomb.
    You should use the <RemovalTool> to check and kill this thing.
    Message<ID>: #
    Attachment: removal-tool.exe

    Message:
    Kaspersky Lab Int. and Norton Anti Virus have found a new typ of worm.
    He calls itself ODIN and he is very variable!
    The worm hides in the screen saver.
    must not embarrasssing to you *laugh*
    Read the -screen_doc- documentation and you will be able to
    find and kill this virus!
    Robot<Transmission>
    Attachment: screen_doc.scr



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: October 24, 2003
Updated: February 13, 2007 12:12:34 PM
Also Known As: W32/Sober@MM [McAfee], I-Worm.Sober [Kaspersky], W32/Sober-A [Sophos], WORM_SOBER.A [Trend]. Sober [F, W32/Sober.A@mm [Frisk], W32/Sober.A [Norman], Win32/Sober.A [Eset], Win32.Sober.A [Computer Associ
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. Restart the computer in Safe mode or VGA mode.
  4. Run a full system scan and delete all the files detected as W32.Sober@mm.
  5. Delete the values that were added to the registry.

For specific 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:

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. 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 VGA mode
Do not skip this step. In most cases there will be two worm processes running on an the infected computer. If one worm process is terminated, the second worm process will immediately start the terminated process.

Shut down the computer and turn off the power. Wait for at least 30 seconds, and then restart the computer in Safe mode or VGA mode.
  • For Windows 95, 98, Me, 2000, or XP users, restart the computer in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."
  • For Windows NT 4 users, restart the computer in VGA mode.


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.
  2. Run a full system scan.
  3. If any files are detected as infected with W32.Sober@mm, write down the file names and then click Delete.


5. Deleting the values from the registry


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.
  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 each of the following keys:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

  4. In the right pane, delete the value that refers to the worm file.

  5. Exit the Registry Editor.


Writeup By: Yana Liu