W32.Degnax@mm

Once executed, the worm creates some or all of the following malicious files:

• %Windir%\security\logs\secure.dll
• %Windir%\security\logs\svchost.exe
• %Windir%\b.dll
• %Windir%\readme.drv
• %Windir%\HRDList.xls
• %System%\WindowsServerService.exe
• %System%\Real.dll
• %Windir%\userinit.exe

It also drops some or all of the following files:

• %Windir%\security\logs\d.dll
• %Windir%\security\logs\Scewin.txt
• %Windir%\security\logs\System32.sys
• %Windir%\help002.hlp
• %Windir%\Scewin.txt
• %Windir%\system32.sys
• %System%\autodisk.sys
• %System%\c.dll
• %System%\e.dll
• %System%\Express.ocx
• %System%\winrun.dll
• %System%\X360OutlookExpress.ocx

It creates the following registry entries so that it executes everytime Windows starts:

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\"SysPrnt"
• HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run\"Help" = "%Windir%\userinit.exe"
• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\"SrvSec" = "%Windir%\security\logs\svchost.exe""
• HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run\"SysSupport" = "%System%\WindowsServerService.exe"
• HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run\"SrvSec" = "%Windir%\security\logs\svchost.exe"

The following registry entries are modified by the worm in an attempt to hide it's presence on the system:

• HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\"Hidden" = "0x00000000"
• HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\"HideFileExt" = "0x00000001"

The worm attempts to download files onto the system and save them as the following:

• %System%\begin.dll
• %System%\SystemPlug.dll

The worm attempts to spread via mapped and network drives. It creates the following files:

• %DriveLetter%\search.exe
• %DriveLetter%\autorun.inf
• %DriveLetter%\ShowSarah.xls
• %DriveLetter%\thumb.log
• %DriveLetter%\win.txt

The worm then gathers contact details from the affected computer and sends a mail to those contacts, where the email has the following characteristics:

Subject:
Any of the following:

• ASAP!!
• Detail...
• Fantastic
• Follow Up
• For All..
• Fw: ASAP!!
• Fw: Date Urgent
• Fw: List Off
• Fw: other project
• Fw: Response Urgent..
• Fw: why ??
• Fw: your advice
• Fw:My Offer
• Gift today
• Global Area
• I'm waiting
• I hope
• I Hope
• Important!!
• In This Area
• Joint?
• Just Info..
• List Off
• Look it now
• Morning!
• Next Step
• Oke!
• Opening soon
• Re: Look it now
• Re: Soon!
• Re: Today
• Re:So you
• Secret!!
• See detail
• sendusing
• Thanks
• This way..
• Time Line
• you too
• Your Friend

Message body:
Any of the following:

• Dear [CONTACTNAME]
  
  Please, to read this detail on attacmnet and give me your best response as soon as possible..!
  
  Thanks a lot!
  Best Regards,
  
  
• Dear [CONTACTNAME]
  
  This email maybe it's too late, but I hope you know this information, couse I know who you are...
  don't forget to give me your response..!
  Rgds,
  
  
• Dear [CONTACTNAME]
  Just for information if you need, sorry... but its up to date..
  See the detail on attachment, I waiting your prompt replay, thx!
  

Attachment:
Any of the following:

• AllProduct.xls
• Budget.xls
• CollectionList.xls
• CompanyBudgetting.xls
• CurriculumVitae.xls
• FantasticOffer.xls
• FYI.xls
• GodBless.xls
• GrandOpening.xls
• HRDList.xls
• itsPossible.xls
• JakartaUnderGround.xls
• Kamasutra.xls
• onSchedule.xls
• PlayboyOffer.xls
• ProductsLowPrice.xls
• ProjectThisMonth.xls
• Technicalads.xls
• TimeFrame.xls

This attachment is a malicious XLS file, containing an embedded copy of W32.Degnax@mm.
The XLS file itself is detected as Trojan.Dropper.

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