Content
W97M/Ethan.a
- Type
- Virus
- SubType
- Macro
- Discovery Date
- 01/21/1999
- Length
- 0
- Minimum DAT
- 4010 (01/27/1999)
- Updated DAT
- 4813 (07/24/2006)
- Minimum Engine
- 5.1.00
- Description Added
- 03/23/1999
- Description Modified
- 11/22/2002 6:44 AM (PT)
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Characteristics
W97M/Ethan.a is a Word97 Macro Virus. It is a fast moving infector and reported to numerous AVERT Labs around the globe. Infection takes place when an infected Word document is closed, allowing the virus to propagate itself to normal.dot template.
W97M/Ethan.A is a parasitic class module infector, which consists of one macro, and is approximately 50 lines of code in length. It infects documents and templates using an algorithm to input data, from a source file
c:\ethan.___
to the host document. This source file is exported VBA code of the virus.
Viruses using class module infection method transfer the virus code to the "ThisDocument" container. This virus prepends its code and infects all documents accessed.
There is a 3-in-10 chance that this virus will modify the document properties of infected files:
Title = "Ethan Frome"
Author = "EW/LN/CB"
These properties will have to be changed back manually after the virus has been removed.
Ethan has one additional characteristic in that if it detects the "class.sys" file (created by the W97M/Class virus infection) on the machine it will delete it.
Symptoms
Existence of file "ethan.___" as mentioned above, changes to document properties as mentioned above.
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 :
* 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
- W97M/Ethan.eo
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
- Ethan Frome
- W97M/Ethan.gen
Characteristics
Characteristics -
W97M/Ethan.a is a Word97 Macro Virus. It is a fast moving infector and reported to numerous AVERT Labs around the globe. Infection takes place when an infected Word document is closed, allowing the virus to propagate itself to normal.dot template.
W97M/Ethan.A is a parasitic class module infector, which consists of one macro, and is approximately 50 lines of code in length. It infects documents and templates using an algorithm to input data, from a source file
c:\ethan.___
to the host document. This source file is exported VBA code of the virus.
Viruses using class module infection method transfer the virus code to the "ThisDocument" container. This virus prepends its code and infects all documents accessed.
There is a 3-in-10 chance that this virus will modify the document properties of infected files:
Title = "Ethan Frome"
Author = "EW/LN/CB"
These properties will have to be changed back manually after the virus has been removed.
Ethan has one additional characteristic in that if it detects the "class.sys" file (created by the W97M/Class virus infection) on the machine it will delete it.
Symptoms
Symptoms -
Existence of file "ethan.___" as mentioned above, changes to document properties as mentioned above.
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 :
* 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 -
- W97M/Ethan.eo
