F-Secure Virus Descriptions : Bubbleboy

    From:    (name of infected user)
    Subject: BubbleBoy is back!
    Body:    The BubbleBoy incident, pictures and sounds

    If you see this on your screen, contact your F-Secure distributor

The reference to Bubbleboy and the above link are references to a character in an episode in the TV show "Seinfeld". Although the link shown by the virus appears to be broken, it is most likely the same page as http://www.toptown.com/dorms/rick/bblboy.htm

This page and it's maintainer have nothing to do with the worm.

The receiver of the e-mail gets infected and spreads the worm without clicking any attachment. The message does not even have any attachments.

When user receives such an e-mail and opens it, the worm attempts to create two files, "C:\WINDOWS\START MENU\PROGRAMS\STARTUP\UPDATE.HTA" and "C:\WINDOWS\MENU INDICIO\PROGRAMS\INICIO\UPDATE.HTA".

These locations specify the Windows startup directory for both English and Spanish versions.

After creating this file the worm will perform no further action until the system has been restarted.

Then the worm will use ActiveX feature to access the system registry. It modifies the Windows registered owner to "BubbleBoy" and organization to "Vandelay Industries".

Then the worm uses ActiveX features to open Outlook and uses it to send itself to all recipients in all address books, like the Melissa virus does.

It also adds a key to the registry to mark that e-mails has been sent:

    HKEY_LOCAL_MACHINE\Software\OUTLOOK.BubbleBoy

and sets its value to:

    OUTLOOK.BubbleBoy 1.0 by Zulu

The mass mailing is done only once per infected machine.

Next, the worm will show a message box with the following text:

    System error, delete "UPDATE.HTA" from the startup folder to solve
    the problem.

When this message appears to the user, the infected e-mails has been sent to all recipients already.

Currently there are two known variants of this worm. The second one is encrypted.

Bubbleboy is able to spread only under Microsoft Outlook 98, Outlook 2000 and Outlook Express that comes with Internet Explorer 5. It does not replicate under Windows NT - instead it just fails without error messages.

Bubbleboy uses a known security hole in Microsoft Outlook to create the local HTA file.

If active scripting is disabled from Outlook, the worm will not work.

Microsoft has more information on this problem available at: http://www.microsoft.com/technet/security/bulletin/fq99-032.asp

They also have a patch to fix this problem at: http://www.microsoft.com/technet/security/bulletin/ms99-032.asp

VARIANT:

BubbleBoy.C

This variant is similar to VBS/BubbleBoy.A.

The message that this variant sends looks like this:

    From:    (name of infected user)
    Subject: From Your Friend...
    Body:    Message From Your Friend...
             http://www.towns.com/dorms/tom/friends.htm

The marker in the registry is different. The marker in this variant is:

    HKEY_LOCAL_MACHINE\Software\OUTLOOK.Friends

and its value is set to:

    OUTLOOK.Friends 1.0 by Wh0

This variant drops a "C:\WINDOWS\FONTS.VBS" file, modifies the settings of the mIRC application and then executes mIRC to send this VBS file. This will work only if mIRC is installed to "C:\MIRC" or "C:\PROGRAM FILES\MIRC" directory.

Then the worm will open a hidden MS-DOS session and will attempt to delete all files from the current directory. Usually this is the Windows directory.

Finally the worm will drop a small binary file, "C:\PrettyIRC.COM". VBS/BubbleBoy.C compiles this file (using the debugger) from a previously dropped source file "C:\WINDOWS\START MENU\PROGRAMS\STARTUP\UPDATE.SCR". This program is supposed to format the hard drive, but it does not work due to a bug.

[Analysis: Katrin Tocheva, Sami Rautiainen and Alexey Podresov, F-Secure]