3DStars is an Internet worm that spreads via e-mail as an attached .EXE file. The worm itself is a Win32 executable file about 70 KB in length, and written in Visual Basic. The worm has many bugs, and in many cases (in all cases in any environment?), doesn't work properly: the worm file is not attached to outgoing messages, and the message text appears different from what the worm intends.
To spread from an affected computer, the worm uses MS Outlook, obtains addresses from the MS Outlook Address Book as well as from the Windows Address Book, and sends messages there. The worm also sends an infected message to email@example.com each time the spreading routine is run.
The message Subject and Body should appear as follows (these do not because of a bug in worm code). The [%CurrentDate%] here is the current date.
- Subject: Hey, now we can talk with this.. :-)
- I wrote a new messenger, so that we can talk with it.
- Install the self extractable zip attached
- Subject: My movie clips..
- I got a webcam, and I captured few movie clips of me.
- Extract the attached self extractable, to see them.
- A lil naughty stuff..
- I got few great, erotic movie clips included in the self extractable
- Subject: I downloaded these MP3s yesterday..
- Hey, they r really great.. Extract the selfextractable zip to see them..
- Subject: Just a little naughty stuff from me..
- See the cake I prepared for you.. bye 4 now buddy..
- Subject: Virus Warning..
- Hey, take care..
- Forward this mail to everyone you know. Today, [%CurrentDate%] FBI
- announced that a serious virus is spreading. It is a file with a .VBS
- extension, much like Love Bug. See the zip for it
- Subject: A Business Issue..
- My company is interested in the opportunities of creating a new
- partnership with you. The presentation is attached, kindly see it and reply soon.
- Subject: Legal Notice..
- We are forced by our client to forward a legal notice to you dated
- [%CurrentDate%]. Kindly see the attached details, and reply as soon as possible
- Subject: Greeting Card 4 You..
- Hope you are doing fine. See the ECard attached 4 you..
When the worm's EXE file is being run from the attachment, it copies itself to the Windows and Windows system directories with SysTray.exe and SysCheck.exe as names, and registers these files in the Windows registry auto-run section:
- SystemTray = %WindowsDir%\SysTray.exe
- SystemCheck = %SystemDir%\SysCheck.exe
Note: the original SYSTRAY.EXE is located in the Windows system directory, not in the Windows directory as the worm does.
To hide its activity, the worm displays the following message:
- Microsoft Windows
- The application %ApplicationName% caused a general protection fault in
- module Kernel.exe, and it will be terminated. Press OK to continue
- [ OK ]
where %ApplicationName% is the worm's file name.
On the 4th of any month, upon being executed before 5 a.m., the worm overwrites the C:\AUTOEXEC.BAT file with a Trojan that erases all files in the "C:\My Documents" and *.DLL files in the C:\Windows directories. The Trojan code also displays the following messages:
- Please wait while setup update files. This may take a few minutes..
- Now loading Windows..
The worm also have backdoor component that "opens" affected computer for a remote hacker. The backdoor routine allows:
- report drives in system, directories and files on drives
- read, write, copy, or delete a file
- change, create, or remove a directory
- read,write registry keys
- send email to a specified address
- execute a file
- force Windows to exit
The worm code contains the text "3DStars server", thus giving the worm name its name.
The worm displays animated stars after the system is rebooted.