Worm:W32/Somali.A

Classification

Malware

Worm

W32

Worm.MSIL.Somali.a

Summary

Somali.A is a mass-mailing worm that terminates security-related processes and blocks antivirus-related software updates.

Removal

Automatic action

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

Find out more

Knowledge Base

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User Guide

See the user guide for your product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details

Somali.A is also capable of opening a port on the infected machine. If a remote user sends strings to the opened port, the worm is able to reply to the remote user.

This malware will only run on Windows platforms that have .NET framework installed.

Execution

Upon execution, Somali.A modifies the registry so that the worm is executed every time a user logs on.

It then drops several copies of itself:

  • %windir%\system32\ctfmon32.exe
  • %rootdir%\project.pif
  • %currentdir%\Project-setup.exe

The worm also displays the following fake error messages:

Note: This message will appear on the first run on a clean machine.

Note: This message will appear if it has been run previously.

Propagation

Somali.A can also propagate through network. It does this by creating a Shared folder:

  • %rootdir%\System33

And then dropping a copy of itself on the shared folder as Sound.exe.

The said shared folder has a share name of MadSoli, as seen in the screenshot below:

Subsequently, it will create the following registry key:

  • [HKLM\System\CurrentControlSet\Services\lanmanserver\Shares] MadSoli = {Multi-String} - See Screenshot:

Somali.A attempts to mass-mail itself using mx4.mail.yahoo.com as its SMTP server.

It searches for Yahoo! email addresses on Windows folder in the files with the following extension names:

  • adb
  • asp
  • cfg
  • cgi
  • dbx
  • eml
  • html
  • pl
  • shtm
  • txt
  • wab
  • xml

Possible Email address of the Sender:

  • antiblaster@yahoo.com
  • avg@yahoo.com
  • bill@yahoo.com
  • bob@yahoo.com
  • ebook@yahoo.com
  • info@yahoo.com
  • iraq@yahoo.com
  • LongShot@yahoo.com
  • matt@yahoo.com
  • mcafee@yahoo.com
  • nod32@yahoo.com
  • panda@yahoo.com
  • smith@yahoo.com
  • stan@yahoo.com
  • steve@yahoo.com
  • symantec@yahoo.com
  • update@yahoo.com
  • YourFriend@yahoo.com
  • CC: software@yahoo.com
  • BCC: crack@yahoo.com

Possible Subjects:

  • Announcement
  • ANTI VIRUS
  • Attention
  • email account disabling warning
  • FBI
  • IranSare2008
  • mcafee
  • NOD32
  • password
  • Read it immediately
  • Soccer funs in public place
  • symantec
  • Text Message
  • Text message
  • Yahoo!
  • Your IP was logged

Possible Message Body:

  • Your email account was used to send a huge amount of unsolicited spam messages during the recent week. If you could please take 5-10 minutes out of your online experiences and confirm the attach document so you will not run into any future problems with the online service.
  • It has come to our attention that your (File!) User Profile ( x )records are out of date. For further details see the attached document. Tank you for using !
  • Thank you for using file
  • +++ Attachment: No Virus (Clean)
  • +++[mcafee] Antivirus - www.mcafee.com
  • Deliver Error
  • Message Error
  • help attached
  • such as yours
  • illegal st. of you
  • I have your password!
  • classroom test of you?
  • old photos about you?

Payload

Somali.A checks the running processes and terminates processes with the following strings:

  • AVGSERV
  • AVGSERV9
  • Clshield
  • DAP
  • GhostTray
  • mghtml
  • NAVW32
  • notepad
  • NTPROTECTED
  • regedit
  • scan32
  • SCAN95
  • taskmgr

The worm creates the following user in the local User Group:

  • User name: NewAdmin Password: MadSoli Comment: Windows pc

Note: Run the following command from the CMD prompt to check for the said user:

  • "net user NewAdmin".

It also deletes all the subkeys on the following registry key:

  • [HKCU\Printers]

Somali.A displays the following Message Box every 19th of the month:

The worm also creates a HOST file named HOST.file in the %windir%\system32\drivers\etc directory. This HOST file will not allow accesses to the following sites:

  • avg.com
  • download.mcafee.com
  • google.com
  • google.com
  • mcafee.com
  • pandasoftware.com
  • symantec.com
  • trendmicro.com
  • update.symantec.com
  • www.24-7-transportation.com
  • www.adhdtests.com
  • www.aegee.org
  • www.aimcenter.net
  • www.alupass.lu
  • www.amanit.ru
  • www.AmirCivil.com
  • www.andara.com
  • www.angelartsanctuary.com
  • www.anthonyflanagan.com
  • www.approved1stmortgage.com
  • www.argontech.net
  • www.asianfestival.nl
  • www.atlantisteste.hpg.com.br
  • www.avg.com
  • www.avg.com
  • www.aviation-center.de
  • www.bbc.com
  • www.bbsh.org
  • www.bga-gsm.ru
  • www.boneheadmusic.com
  • www.bottombouncer.com
  • www.bradster.com
  • www.buddyboymusic.com
  • www.bueroservice-it.de
  • www.calderwoodinn.com
  • www.capri-frames.de
  • www.celula.com.mx
  • www.ceskyhosting.cz
  • www.chinasenfa.com
  • www.cntv.info
  • www.compsolutionstore.com
  • www.coolfreepages.com
  • www.corpsite.com
  • www.couponcapital.net
  • www.cpc.adv.br
  • www.crystalrose.ca
  • www.cscliberec.cz
  • www.curtmarsh.com
  • www.customloyal.com
  • www.DarrkSydebaby.com
  • www.deadrobot.com
  • www.dontbeaweekendparent.com
  • www.download.mcafee.com
  • www.dragcar.com
  • www.ecofotos.com.br
  • www.eurostavba.sk
  • www.everett.wednet.edu
  • www.fcpages.com
  • www.featech.com
  • www.FritoPie.NET
  • www.google.com
  • www.mcafee.com
  • www.microsoft.com
  • www.my-etrust.com
  • www.pandasoftware.com
  • www.symantec.com
  • www.trendmicro.com
  • www.update.symantec.com
  • www.viruslist.com
  • www.yahoo.com
  • yahoo.com

Backdoor

Somali.A opens TCP port 8051. If a remote hacker connects to the said port and sends strings through this port, Somali.A will reply with the same string with all capital letters and adds exclamation mark at the end of the string.

Registry

Somali.A creates the following auto-run registry key so that every time the user logs on, Somali.A will be executed:

  • [HKCU\Software\Microsoft\Windows\Currentversion\Run] Services32.bak = %windi%\system32\ctfmon32.exe

For its signature, it creates the following registry key:

  • [HKCU\MadSoli] MadSoli = "System"

It creates a Mutex named MadSoli so that there will be only one instance of itself in the memory.

Date Created: 2006-08-29 08:24:59.0

Date Last Modified: 2010-07-13 05:44:13.0