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  3. W32.Mabezat.B

W32.Mabezat.B

Risk Level 2: Low

Discovered:
December 1, 2007
Updated:
December 2, 2007 12:17:56 PM
Also Known As:
W32/Mabezat-B [Sophos], Worm:W32/Mabezat.B [F-Secure], Win32/Mabezat.B [Computer Associates], Worm:W32/Mabezat [F-Secure]
Type:
Worm
Infection Length:
154,751 bytes (exe), 32,768 bytes (DLL)
Systems Affected:
Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows Vista, Windows XP
Once executed, the worm copies itself as the following files:
  • %SystemDrive%\Documents and Settings\tazebama.dl_
  • %SystemDrive%\Documents and Settings\hook.dl_
  • %UserProfile%\Start Menu\Programs\Startup\zPharoh.exe

It also drops the following file:
%SystemDrive%\Documents and Settings\tazebama.dll

The worm then creates the following folder and files:
  • %SystemDrive%\Documents and Settings\[USER NAME]\Application Data\tazebama
  • %SystemDrive%\Documents and Settings\[USER NAME]\Application Data\tazebama\tazebama.log
  • %SystemDrive%\Documents and Settings\[USER NAME]\Application Data\tazebama\zPharaoh.dat

The worm deletes the following registry entry to reset the drive auto run settings to default:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\NoDriveTypeAutoRun

The worm also sets the following registry key to hide system files:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\"ShowSuperHidden" = "0"

Next, the worm creates the following files on remote or mapped drives:
  • [DRIVE]:\zPharaoh.exe
  • [DRIVE]:\autorun.inf

Then the worm searches for .exe files on the compromised computer and infects them by performing the following actions:
  • Encrypts the original file
  • Updates its resource data, so that it displays the icon of the original file.

The infected files are detected as W32.Mabezat.B!inf.

The worm also attempts to copy itself through network shares protected by weak passwords using the following user names:
  • anonymous
  • administrator

Then the worm copies itself to the network shares using the following file names:
  • My documents .exe
  • Readme.doc .exe
  • My Documents [SPACES].exe

The worm may then send emails with the following characteristics:

Subject: ABOUT PEOPLE WITH WHOM MATRIMONY IS PROHIBITED
Attachment: PROHIBITED_MATRIMONY.rar
Body:
1 : If a man commits adultery with a woman, then it is not permissible for him to marry her mother o [REMOVED] ith a woman, because prohibited for her mother and daughters. Download the attached article to read.

Subject: Windows secrets
Attachment: FolderPW_CH(1).rar
Body:
The attached article is on "how to make a folder password". If your are interested in this article download it, if you are not delete it.

Subject: Canada immigration
Attachment: IMM_Forms_E01.rar
Body:
The debate is no longer about whether Canada should remain open to
immigration. That debate becam [REMOVED] the required forms. The sender of this email got this article from our side and forwarded it to you.

Subject: Viruses history
Attachments: virushistory.rar
Body:
Nowadays, the viruses have become one of the most dangerous systems to attack the computers. There a [REMOVED] load the attached and decompress It by WinRAR. The sender has red the story and forwarded it to you.

Subject: Web designer vacancy
Attachment: JobDetails.rar
Body:
Fortunately, we have recently received your CV/Resume from moister web site and we found it matching [REMOVED]
Thanks & Regards,
Ajy Bokra
Computer department.
AjyBokra@webconsulting.com

Subject: MBA new vision
Attachment: Marketing.rar
Body:
MBA (Master of business administration ) one of the most required degree around the world. We offer [REMOVED] Ajy klaf
AjyKolav@tazeunv.com
The sender has added your name to be informed with our services.

Subject: problem
Attachment: outlooklog.rar
Body:
When I had opened your last email I received some errors have been saved in the attached file. Please inform me with those errors as soon as possible.

Subject: hi
Attachment: notes.rar
Body:
Unfortunately, I received unformatted email with an attached file from you. I couldn't understand what is behind the words. I wish you next time send me a readable file!. I forwarded the attached file again to evaluate your self.


The worm may use other email attachment file names including the following:
  • windows.rar
  • office_crack.rar
  • serials.rar
  • passwords.rar
  • windows_secrets.rar
  • source.rar
  • imp_data.rar
  • documents_backup.rar
  • backup.rar
  • MyDocuments.rar
  • HpphmfUppmcbsOpujgjfs/fyf
  • GoogleToolbarNotifier.exe
  • PanasonicDVD_DigitalCam.exe
  • Antenna2Net.exe
  • RadioTV.exe
  • Microsoft MSN.exe
  • Sony Erikson DigitalCam.exe
  • IDE Conector P2P.exe
  • Windows Keys Secrets.exe
  • FaxSend.exe
  • RecycleBinProtect.exe
  • Disk Defragmenter.exe
  • CD Burner.exe
  • ShowDesktop.exe
  • BrowseAllUsers.exe
  • LockWindowsPartition.exe
  • Win99compatibleXP.exe
  • MakeUrOwnFamilyTree.exe
  • WindowsXp StartMenu Settings.exe
  • Recycle Bin.exe
  • Adjust Time.exe
  • Microsoft Windows Network.exe
  • HP_LaserJetAllInOneConfig.exe
  • FloppyDiskPartion.exe
  • msjavx86.exe
  • AmericanOnLine.exe
  • Crack_GoogleEarthPro.exe
  • Lock Folder.exe
  • InstallMSN11En.exe
  • InstallMSN11Ar.exe
  • JetAudio dump.exe
  • KasperSky6.0 Key.doc.exe
  • Office2007 Serial.txt.exe
  • Office2007 CD-Key.doc.exe
  • Make Windows Original.exe
  • NokiaN73Tools.exe
  • WinrRarSerialInstall.exe

It also copies the following files to %UserProfile%\Local Settings\Application Data\Microsoft\CD Burning so that any CD burnt will contain the worm.
  • zPharaoh.exe
  • autorun.inf

It may then encrypt files with the following extension:
  • .hlp
  • .pdf
  • .html
  • .txt
  • .aspx.cs
  • .aspx
  • .psd
  • .mdf
  • .rtf
  • .htm
  • .ppt
  • .php
  • .asp
  • .pas
  • .h
  • .cpp
  • .xls
  • .doc
  • .rar
  • .zip
  • .mdb

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: Elia Florio
Summary| Technical Details| Removal

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