WM/ZMB.A:DE

This page shows details and results of our analysis on the malware WM/ZMB.A:DE

Download Current DAT: 6712

Threat Detail

Malware Type: Virus

Malware Sub-type: Macro

Discovery Date: 1997-07-01

Next Steps:

Overview
Characteristics
Symptoms
Method of Infection
Removal

Overview

This is a virus detection. Viruses are programs that self-replicate recursively, meaning that infected systems spread the virus to other systems, which then propagate the virus further. While many viruses contain a destructive payload, it's quite common for viruses to do nothing more than spread from one system to another.

Minimum DAT

4002 (1998-12-02)

Updated DAT

4002 (1998-12-02)

Minimum Engine

5.1.00

File Length

Not Applicable

Description Added

1997-07-15

Description Modified

1997-07-15

Malware Proliferation

Characteristics

This virus propagates by infecting Word Documents in Microsoft WORD Versions 6.x / 7.x on Windows and Macintosh platforms. The virus consists of these macros:

AUTOOPEN, DATEIDRUCKEN, DATEISPEICHERN, EXTRASMAKRO

in an infected document. Their names change to:

ZMB, DATEIDRUCKEN, DATEISPEICHERN, EXTRASMAKRO

in Word's Global Template NORMAL.DOT. The virus becomes active by using AutoMacros. Its spreading activity remains only in the german language version of Microsoft Word. However, the virus may be able to execute its payload in another language version. All macros are encrypted using the standard Word execute-only feature. Meaning that the user is unable to edit or view the macro code. The virus can carry along other macros with it, so an infected file can potentially contain many macros.

Symptoms

On an infected system the virus emulates the EXTRASMAKRO functionality. Warning: It is important not to use this command, as you will execute the viral code. When using the DATEISPEICHERN command on March 31 it will delete the files C:\CONFIG.SYS and C:\AUTOEXEC.BAT. Then a MessageBox like

Osterhasenpolizei

Hallihallo . . . Ich bin der Osterhase und sage Dir, da man an Ostern keinen Computer benutzen soll !!

is displayed. When the DATEI|DRUCKEN command is used there is a [1]-in-[3] chance that it will run a text replace routine, most are pretty funny if you know German! There are 8 possible text replacement procedures:

1: Blut replaced by Sperm, hei replaced by kalt.

2: hell replaced by dunkel, Lampe replaced by Schlampe, weich replaced by hart.

3: links replaced by rechts, linke replaced by rechte.

4: whrend replaced by werend, nmlich replaced by nehmlich, Produkt replaced by Quotient.

5: geehrte replaced by gehrte, Damen replaced by Samen.

6: freundliche Gren replaced by stinkingen Fen, Bestellung replaced by Bestehlung, Nase replaced by Vagina.

7: der replaced by das, dem replaced by wem.

8: die replaced by sie, Ihnen replaced by Dir.

It will always replace Rauschnabel with Sauschnabel.

Method of Infection

General Macro Virus Information

Removal

All Users :
Script,Batch,Macro and non memory-resident:
Use current engine and DAT files for detection and removal.

PE,Trojan,Internet Worm and memory resident :
Use specified engine and DAT files for detection. To remove, boot to MS-DOS mode or use a boot diskette and use the command line scanner:

SCANPM /ADL /CLEAN /ALL

Additional Windows ME/XP removal considerations

Users should not trust file icons, particularly when receiving files from others via P2P clients, IRC, email or other mediums where users can share files.

AVERT Recommended Updates :

* Office2000 Updates

* Malformed Word Document Could Enable Macro to Run Automatically (Information/Patch )

* scriptlet.typelib/Eyedog vulnerability patch

* Outlook as an email attachment security update

* Exchange 5.5 post SP3 Information Store Patch 5.5.2652.42 - this patch corrects detection issues with GroupShield

For a list of attachments blocked by the Outlook patch and a general FAQ, visit this link .
Additionally, Network Administrators can configure this update using an available tool - visit this link for more information .

It is very common for macro viruses to disable options within Office applications for example in Word, the macro protection warning commonly is disabled. After cleaning macro viruses, ensure that your previously set options are again enabled.