McAfee > Theat Center > Virus Detail Page

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.

Aliases

• Macro.Word97.Thus.a

• Thus.a

• W97M/Thursday

• W97M/Thus.gen

Characteristics

This is a virus that infects Word 97 documents. The virus consists of a module called ThisDocument. It will infect Word's normal.dot file. When it infects it turns the Word 97 Macro Warning feature off.

Prior to infecting a document, the virus will look to see if it has already infected the document by checking for a comment - thus.000 - if this comment is found the virus will not reinfect.

On the 13th of December when an infected document is opened the virus will attempt to delete ALL files on drive C: (including subdirectories).

This virus has been reported to AVERT by various banks and financial organizations in Europe and the United States. This virus DOES NOT use email to spread itself, however as in many cases it can get from one place to the next as an attachment in an email message.

Symptoms

Macro warning when opening infected documents on non-infected system.

Method of Infection

Opening infected documents will directly infect the local Word environment and any document used thereafter.

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:

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.

Variants

Variants

N/A

All Information

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.

Aliases

• Macro.Word97.Thus.a

• Thus.a

• W97M/Thursday

• W97M/Thus.gen

Characteristics

Characteristics -

This is a virus that infects Word 97 documents. The virus consists of a module called ThisDocument. It will infect Word's normal.dot file. When it infects it turns the Word 97 Macro Warning feature off.

Prior to infecting a document, the virus will look to see if it has already infected the document by checking for a comment - thus.000 - if this comment is found the virus will not reinfect.

On the 13th of December when an infected document is opened the virus will attempt to delete ALL files on drive C: (including subdirectories).

This virus has been reported to AVERT by various banks and financial organizations in Europe and the United States. This virus DOES NOT use email to spread itself, however as in many cases it can get from one place to the next as an attachment in an email message.

Symptoms

Symptoms -

Macro warning when opening infected documents on non-infected system.

Method of Infection

Method of Infection -

Opening infected documents will directly infect the local Word environment and any document used thereafter.

Removal -

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:

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.

Variants

Variants -

N/A