SymbOS.Commwarrior.B

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Discovered: March 07, 2005
Updated: February 13, 2007 12:34:59 PM
Also Known As: SymbOS/Commwarrior.b!sys [McAf
Type: Worm
Systems Affected: EPOC


SymbOS.Commwarrior.B is a worm that replicates on the Symbian OS, which is used as the operating system for Nokia Series 60 cellular telephones. It attempts to spread using Multimedia Messaging Service (MMS) and Bluetooth as a randomly named .sis file. If it is the first hour of the 14th of any month, the threat resets the device.

Note: Virus definitions released March 8, 2005 may detect this threat as SymbOS.Commwarrior.A.



Symantec recommends the following to protect against this threat:

  • If Bluetooth is not required, it should be turned off.
  • If you require the use of Bluetooth, ensure that the device's visibility setting is set to "Hidden" so that it can not be scanned by other Bluetooth devices.
  • Avoid use of device pairing. If it must be used, ensure that all paired devices are set to "Unauthorized". This requires each connection request to be authorized by the user.
  • Do not accept unsigned applications (no digital signature) or applications sent from unknown sources. Be absolutely sure of the origin of the application before accepting it.

Symantec offers a security solution for Symbian known as Symantec Client Security for Nokia Communicators. This product can be downloaded via the Nokia 9500/9300 web browser or from a PC. Symantec will never send unsolicited messages regarding one of our products. For additional information please see http://www.symantec.com/smallbiz/nok .

Antivirus Protection Dates

  • Initial Rapid Release version March 09, 2005
  • Latest Rapid Release version January 15, 2018 revision 004
  • Initial Daily Certified version March 09, 2005
  • Latest Daily Certified version March 23, 2017 revision 041
  • Initial Weekly Certified release date March 09, 2005

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

Writeup By: Eric Chien, Peter Ferrie

Discovered: March 07, 2005
Updated: February 13, 2007 12:34:59 PM
Also Known As: SymbOS/Commwarrior.b!sys [McAf
Type: Worm
Systems Affected: EPOC


When SymbOS.Commwarrior.B arrives at a target device, it may perform the following actions:

  1. Creates the following files on the phone:

    • \system\apps\commwarrior\commwarrior.exe
    • \system\apps\commwarrior\commrec.mdl
    • \system\updates\commwarrior.exe (24,516 bytes)
    • \system\updates\commrec.mdl (2152 bytes)
    • \system\updates\commw.sis (27,162 bytes)

      Note: The only difference between SymbOS.Commwarrior.B and SymbOS.Commwarrior.A is the size of the files dropped.

  2. Runs and executes commwarrior.exe at system startup from the recognizer file in c:\system\recogs\commrec.mdl. This will allow the process to continue.

  3. Rebuilds an .sis file from the above files into the following location:

    \system\updates\commw.sis

  4. Searches for nearby Bluetooth-enabled devices and attempts to send a randomly named copy of the .sis file, every minute, to all devices that it finds.

  5. Randomly choose a contact phone number from the device's phonebook and sends an MMS message containing the commw.sis file as an attachment. The MIME type of the attachment is application/vnd.symbian.install.

    The MMS messages have the following characteristics:

    • Subject: Norton AntiVirus
      Message: Released now for mobile, install it!
    • Subject: 3DGame
      Message: 3DGame from me. It is FREE !
    • Subject: 3DNow!
      Message: 3DNow!(tm) mobile emulator for *GAMES*.
    • Subject: Audio driver
      Message: Live3D driver with polyphonic virtual speakers!
    • Subject: CheckDisk
      Message: *FREE* CheckDisk for SymbianOS released!MobiComm
    • Subject: Desktop manager
      Message: Official Symbian desctop manager.
    • Subject: Display driver
      Message: Real True Color mobile display driver!
    • Subject: Dr.Web
      Message: New Dr.Web antivirus for Symbian OS. Try it!
    • Subject: Free SEX!
      Message: Free *SEX* software for you!
    • Subject: Happy Birthday!
      Message: Happy Birthday! It is present for you!
    • Subject: Internet Accelerator
      Message: Internet accelerator, SSL security update #7.
    • Subject: Internet Cracker
      Message: It is *EASY* to *CRACK* provider accounts!
    • Subject: MS-DOS
      Message: MS-DOS emulator for SymbvianOS. Nokia series 60 only. Try it!
    • Subject: MatrixRemover
      Message: Matrix has you. Remove matrix!
    • Subject: Nokia ringtoner
      Message: Nokia RingtoneManager for all models.
    • Subject: PocketPCemu
      Message: PocketPC *REAL* emulator for Symbvian OS! Nokia only.
    • Subject: Porno images
      Message: Porno images collection with nice viewer!
    • Subject: PowerSave Inspector
      Message: Save you battery and *MONEY*!
    • Subject: Security update #12
      Message: Significant security update. See www.symbian.com
    • Subject: Symbian security update
      Message: See security news at www.symbian.com
    • Subject: SymbianOS update
      Message: OS service pack #1 from Symbian inc.
    • Subject: Virtual SEX
      Message: Virtual SEX mobile engine from Russian hackers!
    • Subject: WWW Cracker
      Message: Helps to *CRACK* WWW sites like hotmail.com

  6. If it is the first hour of the 14th of any month, the threat resets the device.


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: Eric Chien, Peter Ferrie

Discovered: March 07, 2005
Updated: February 13, 2007 12:34:59 PM
Also Known As: SymbOS/Commwarrior.b!sys [McAf
Type: Worm
Systems Affected: EPOC


Removal using the Symantec Mobile Threats Removal Tool
Symantec Security Response has developed a removal tool to clean the infections of SymbOS.Commwarrior.B. Use this removal tool first, as it is the easiest way to remove this threat.

Manual Removal:

To remove SymbOS.Commwarrior.B:

  1. Install a file manager program on the phone.
  2. Enable the option to view the files in the system directory.
  3. Search the drives, A through Y, for the \system\apps\commwarrior directory.
  4. Delete the files commwarrior.exe and commrec.mdl.
  5. Go to the \system\updates\commwarrior directory.
  6. Delete the files commwarrior.exe, commrec.mdl, and commw.sis.
  7. Go to the \system\recogs directory.
  8. Delete the file commrec.mdl.


Writeup By: Eric Chien, Peter Ferrie