W32.Spamuzle.D

Once executed, the worm drops the following files:

• %System%\[RANDOM NAME]
• %System%\bmf.cs
• %System%\ccs.so
• %System%\gh.l
• %System%\mn.n
• %System%\ntpl.bin
• %System%\nvrsma.dll
• %System%\yl.po

It may also create the following files:

• %System%\acl.exe
• %System%\MarioForever.exe
• %DriveLetter%\MarioForever.exe

The worm then modifies the following files:

• %System%\dllcache\user32.dll
• %System%\user32.dll

Next, it creates the following registry entries:

• HKEY_LOCAL_MACHINE\SOFTWARE\[NUMBER]\"[34 DIGIT HEX NUMBER]" = "[RANDOM DATA]"
• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows\"ztpInit_Dlls" = "nvrsma"
• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\"ccnt" = "[NUMBER OF INFECTION ATTEMPTS]"
• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\"mid" = "[RANDOM HEX DATA]"

The worm may delete registry subkeys containing the following strings to lower security settings:

• *\shellex\ContextMenuHandlers\NOD32 Context Menu Shell Extension
• AllFilesystemObjects\shellex\ContextMenuHandlers\SpySweeper
• ALWIL Software\Avast
• Arovax AntiSpyware
• Chilkat Software, Inc.
• ComputerAssociates\eTrustPestPatrol
• Doctor Web, Ltd.
• FRISK Software International
• Grisoft\AVGAntiSpyware
• KasperskyLab
• McAfee\McAfee AntiSpyware
• McAfee\VirusScan
• Panda Software
• PepiMK Software\SpybotSnD
• SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Ad-aware 6 Personal
• SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Ad-Aware SE Personal
• SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\AntiVir PersonalEdition Classic
• SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\ClamAV
• SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\SpywareBlaster_is1
• SOFTWIN\BitDefender Desktop\Maintenance\Install
• Spyware Begone!
• Symantec\Symantec AntiVirus
• SYSTEM\ControlSet001\Services\avgntflt
• SYSTEM\CurrentControlSet\Services\WinDefend
• Ukranian Antivirus center
• Vba32
• VMware, Inc.
• VMware, Inc.\VMware Tools

The worm creates a service with the following characteristics so that it runs when Windows starts:
Service name: SCNa
Display name: SCNa Service
Startup Type: Automatic

It registers the service by creating and populating the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SCNa

The worm may contact the following remote locations to report infection notification and download configuration data as well as possibly update itself:

• [http://]66.36.241.45/sdb/gate/[REMOVED]
• [http://]66.36.241.45/sdb/gate/data[REMOVED]

The worm then attempts to spread through network shares using the following passwords:

• !@#
• 1212
• 123
• 123456
• 1313
• 666
• 777
• adm
• admin
• administrator
• administrator
• asa
• pass
• password
• qaz
• qazxsw
• qqq
• qwerty
• test
• zaq
• zaqwsx
• zzz

It then attemps to copy itself as the following file:
%DriveLetter%\acl.exe

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.

Summary