Virus Profile: W97M/Marker.o

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Virus Profile information details
Risk Assessment: Home Low | Corporate Low
Date Discovered: 6/3/1999
Date Added: 9/7/1999
Origin: N/A
Length: N/A
Type: Virus
Subtype: Macro
DAT Required: 4030
Removal Instructions


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

Message boxes as mentioned above, macro warning when opening infected documents in non-infected systems.

Methods of Infection

Opening infected document will directly infect the global template NORMAL.DOT which will infect any document used in the Word environment.

Virus Characteristics

The W97M/Marker.O virus was first listed as 'In The Wild' on The WildList in August 1999. At the time of this writing, this virus is widespread in India.

W97M/Marker.O is quite different than W97M/Marker.C and W97M/Marker.D - two other 'Marker' variants also listed on The WildList.

W97M/Marker.O infects Word 97 documents. It will turn off the macro warning feature of Word 97. This virus consists of a module called ThisDocument.

W97M/Marker.O will infect MS-Word's NORMAL.DOT file

W97M/Marker.O contains the following string (which is never displayed to the screen) in its code:

":-D you are marked!"

Upon closing a document, if the date is the 23rd or greater and the month is July (in other words when the date is July 23rd through July 31), the virus displays the following message box:

Did You Wish Shankar on his Birthday ?

Upon opening an infected document, the same message box as above is displayed. However, the following screens apply to documents only when they are closed.

If the user clicks the 'Yes' answer box, the following message is displayed:

Thank You! I Love You. You are wonderfull.

If the user clicks the 'No' answer box, the following message is displayed:

You are Heart Less You Will Be Punished For This

Upon creating a new document, an animation is displayed to the screen. The animation is made up of large block letters that spell out 'Happy Birthday Shankar'. However, because the font size is so large (72pt) - on computers with a lower display resolution - 'Happy' may scroll off the top of the screen. The letters in the message are green in color with an animated sparkling background.

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:


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.


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