W97M/Yous

This page shows details and results of our analysis on the malware W97M/Yous

Download Current DAT: 6614

Threat Detail

Malware Type: Virus

Malware Sub-type: Macro

Discovery Date: 2000-10-26

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

4102 (2000-11-01)

Updated DAT

4102 (2000-11-01)

Minimum Engine

5.1.00

File Length

N/A

Description Added

2000-11-01

Description Modified

2002-09-18

Malware Proliferation

Characteristics

This virus propagates by infecting Word Documents in Microsoft Word97 and Word2000. The virus consists of a macro "ThisDocument". When an infected document is opened the virus performs the following tasks:

- Disable Word's macro warning prompt
- Disable Word's file conversion prompt
- Disable Word's save normal template prompt
- Launches the last ran command from START|Run, either minimized or hidden from the user
- On the 12th To 22nd day of the month, changes the default network logon name, computer name and current username to the computer name with a random last character

Symptoms

Altered default network logon name, computer name and current username

Method of Infection

The virus writes its code to the global template, "Normal.dot". Once the global template is infected, all documents used on the system will become infected.

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.