Threat Explorer

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VBS.NewLove.A

VBS.NewLove.A

Updated:
13 February 2007
Also Known As:
VBS/Loveletter.ed, VBS/Loveletter.Gen, VBS_SPAMMER, VBS.Loveletter.FW.A

SARC, in conjunction with other anti-virus vendors, has renamed this worm from VBS.LoveLetter.FW.A to VBS.NewLove.A.

The VBS.NewLove.A is a worm, and spreads by sending itself to all addresses in the Outlook address book when it is activated. The attachment name is randomly chosen, but will always have a .Vbs extension. The subject header will begin with "FW: " and will include the name of the randomly chosen attachment (excluding the .VBS extension) Upon each infection, the worm introduces up to 10 new lines of randomly generated comments in order to prevent detection.

Antivirus Protection Dates

  • Initial Rapid Release version 18 May 2000
  • Latest Rapid Release version 19 February 2013 revision 016
  • Initial Daily Certified version 18 May 2000
  • Latest Daily Certified version 04 February 2011 revision 020
  • Initial Weekly Certified release date pending
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

This polymorphic Loveletter variant will overwrite ALL files that are not currently in use regardless of extension. It arrives as an email message with a subject of "FW: FILENAME.EXT" and an attachment named "FILENAME.EXT.VBS" (where FILENAME.EXT is derived from the infected user's recently opened documents list.) The body of the email is empty. If no documents have been used recently, this name is randomly generated. If the message has been generated by a system running Windows NT or Windows 2000, then the file name is omitted and the subject of the message is "FW: .EXT" and the attachment name is ".EXT.VBS" (again, the file extension varies depending on the recently opened documents list of infected machines).

Registry entries modified:
HKLM\Software\Microsoft\Windows\CurrentVersion\Run\ HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices\

The actual key name will be the filename that is attached to the email. However for the Run key, it will be
randomname = WindowsSystemDir \ randomname.ext.VBS

and the RunServices will be
randomname = WindowsDir \ randomname.ext.VBS

Please also be aware it will create the following files, where <randomname> is the name of the file attachment of the email:
  • WindowsSysDir\randomname.Ext.VBS
  • WindowsDir\randomname.Ext.VBS
  • WindowsSystemDir\RecentUsedFile.Ext.VBS

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.

The contents of all files will be deleted, leaving the affected files with a byte length of zero.

The worm also appends the .vbs extension to each of these files. For example, the calc.exe file becomes calc.exe.vbs.

Because this worm overwrites all files regardless of extension, proper removal can only be achieved by restoring the affected files from known clean backups. The user may need to reinstall the operating system as well as system files may have been destroyed.
Writeup By: Andy Cianciotto