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Virus Profile: Twno.A

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Virus Profile information details
Risk Assessment: Home Low | Corporate Low
Date Discovered: 1/1/0001
Date Added: 11/30/1998
Origin: Taiwan
Length: Not Applicable
Type: Virus
Subtype: Macro
DAT Required: 4002
Removal Instructions
   
 
 
   

Description

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.

Indication of Infection

Twno1 will show a game of mental arithmetic on the 13th of every month. If you answer wrong, the system will open 20 document files for each question. Windows may run slower and slower.

The Twno1 macro virus contains these following macros when it infects a DOT file:

AutoClose
AutoNew
AutoOpen

Methods of Infection

General Macro Virus Information
   

Virus Characteristics

Twno1 is an overwriting, encrypting macro virus. In the Microsoft Word environment, Twno1 infects .DOC and .DOT files and is language dependent
   
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.