Threat Explorer

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VBS.Jolin.int

VBS.Jolin.int

Discovered:
28 June 2001
Updated:
13 February 2007
Also Known As:
VBS/Niloj-A

This script is intended to be a mass-mailing worm that spreads using mIRC and Microsoft Outlook. The samples of the worm that the Symantec AntiVirus Research Center (SARC) has received from customers were not able to spread due to bugs in the worm's code. Because of this, on July 5, 2001, the threat assessment was downgraded from level 2 to level 1.

NOTE: Virus definitions prior to June 28, 2001, detect this worm as Bloodhound.VBS.Worm



All samples received by SARC have a minor bugs in them which cause the worm not to work as intended.

Antivirus Protection Dates

  • Initial Rapid Release version 28 June 2001
  • Latest Rapid Release version 07 May 2019 revision 006
  • Initial Daily Certified version 28 June 2001
  • Latest Daily Certified version 07 May 2019 revision 008
  • Initial Weekly Certified release date pending
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

NOTE: This script contains code which has certain intentions, but due to bugs in the worm's code, the intended actions do not actually occur. The following is a description of what the worm was designed to do.

If this worm did work as designed, it would:
  1. Send itself to all addresses in your Microsoft Outlook Address Book as:

    Subject: FW: Check this out...
    Message: This was the first naked picture taken by a Taiwan singer! Jolin... please don't get over steam by staring at the picture! keke~
    Attachment: !!jolin_caught_naked!!!!.jpg.vbs
  2. Modify the mIRC Script.ini file. This would cause the worm to send itself to others when you are using IRC.
  3. Delete all .exe, .dll, and .inf files from the \Windows\System folder.
  4. Overwrite .zip, .mps, and .mpeg files that are in the \My Documents folder with a copy of itself.
  5. Attempt to copy itself to floppy disks.


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.

NOTE: If you did execute a working version of the worm, (none of which have been submitted to SARC as of this writing) it is likely that Windows would no longer function correctly. In that case, you would need to reinstall Windows and then follow these steps:
  1. Run LiveUpdate to make sure that you have the most recent virus definitions.
  2. Start Norton AntiVirus (NAV), and run a full system scan, making sure that NAV is set to scan all files.
  3. Delete any files detected as VBS.Jolin.int.


Writeup By: Neal Hindocha