Parent class: VirWare

Viruses and worms are malicious programs that self-replicate on computers or via computer networks without the user being aware; each subsequent copy of such malicious programs is also able to self-replicate. Malicious programs which spread via networks or infect remote machines when commanded to do so by the “owner” (e.g. Backdoors) or programs that create multiple copies that are unable to self-replicate are not part of the Viruses and Worms subclass. The main characteristic used to determine whether or not a program is classified as a separate behaviour within the Viruses and Worms subclass is how the program propagates (i.e. how the malicious program spreads copies of itself via local or network resources.) Most known worms are spread as files sent as email attachments, via a link to a web or FTP resource, via a link sent in an ICQ or IRC message, via P2P file sharing networks etc. Some worms spread as network packets; these directly penetrate the computer memory, and the worm code is then activated. Worms use the following techniques to penetrate remote computers and launch copies of themselves: social engineering (for example, an email message suggesting the user opens an attached file), exploiting network configuration errors (such as copying to a fully accessible disk), and exploiting loopholes in operating system and application security. Viruses can be divided in accordance with the method used to infect a computer:
  • file viruses
  • boot sector viruses
  • macro viruses
  • script viruses
Any program within this subclass can have additional Trojan functions. It should also be noted that many worms use more than one method in order to spread copies via networks.

Class: Virus

Viruses replicate on the resources of the local machine. Unlike worms, viruses do not use network services to propagate or penetrate other computers. A copy of a virus will reach remote computers only if the infected object is, for some reason unrelated to the virus function, activated on another computer. For example: when infecting accessible disks, a virus penetrates a file located on a network resource a virus copies itself to a removable storage device or infects a file on a removable device a user sends an email with an infected attachment.

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Platform: MSWord

Microsoft Word (MS Word) is a popular word processor and part of Microsoft Office. Microsoft Word files have a .doc or .docx extension.


Technical Details

This is a stealth macro-virus. It contains eighteen procedures in one module "xSebelas": xSebelasInit, AntiMakro, DisplayPath4, Mcopy, ShowForm, FileOpen, AutoOpen, ViewVBCode, AutoExec, AutoExit, ToolsMacro, FileTemplates, FormatStyle, ReFresh, AutoClose, FileExit, ToolsOptions, and HelpAbout.

The virus infects the global macros area upon opening an infected document (AutoOpen), and infects other documents upon opening and closing (AutoOpen and AutoClose). Upon exiting MS Word, the virus also creates two infected documents in the MS Word start-up directory: these documents have the names BIOS.VXD and WINSSPI.DOT.

The virus turns off the Word virus protection (the VirusProtection option), hides the Tools/Macro menu (stealth), and blocks Visual Basic editor opening.

Upon opening any document, the virus checks the system date and displays the following messages:

on February 4th:

eX-Sebelas release 3.9
'Met ulang tahun Natalie Imbruglia !

on November 1st:

eX-Sebelas release 3.9
'Met ulang tahun Erry Delphiero !

on October 7th:

eX-Sebelas release 3.9
'Met ulang tahun DaNnY DeSPiRo !

On the 11th of every month starting from April 11, 1999, the virus sets to white the font color for the whole text in a document (hides the text - white on white), and then inserts, into the end of the document, the text (with black color):

Viva eX-SeBeLaS !

Starting from April 11, 1999, the virus, every 30 minutes, displays a dialogue window with a picture. The same dialogue window is displayed upon entering the Help/About menu.

Also starting from April 11, 1999, upon exiting MS Word, the virus renames the AUTOEXEC.BAT file to XSEBELAS.BAT and creates a new AUTOEXEC.BAT file that calls the original program (stored in XSEBELAS.BAT) and then displays the text:

|                       eX-SeBeLaS release 3.9                       |
|          [ special dedicated to Natalie 'Jane' Imbruglia ]         |
| DaNnY DeSPiRo :                                                    |
| Salam saya buat anak-anak SMAN 11 Bandung, Analisis Kimia - UNPAD, |
| Delapan Makhluk Cute (DMC), QLas (KIR SMUN 11 Bandung), 'truz buat |
| Jihan Fahira (kapan kamu mampir ke rumah lagi ? e-mail saya dong), |
| teman-teman saya di alam fana ini dan spesial buat cewek lucu yang |
| mirip Natalie Imbruglia ...                  [] |
| ErRy DeLPhIeRo :                                                   |
| BuAT aNAk-AnAk AMIK-SuKapURa TSM, AMIK-BaNDuNg, DJEPROETH '95, 'en |
| BaRuDaK TeAtEr NuAnSa, BuAt GadSam '95 : DoNt FoRgEt Me ... E-MaiL |
| GuE YaCh ... Buat ANaK-aNAk 'ACC', Buat GaDiS-GaDIs  YaNG CaRe 'en |
| MaU KeNAlaN AMa ErRy di TuNGgU LHo e-maiLnyA, 'en SpECiaL SmILe To |
| LuTju GiRl NaTaLiE ImBrUgLiA !             [] |
| ... sorry for sending you a virus (maybe more than one), we just - |
| want to prove to ourselves that  virus programming is very fun ... |

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