W97M/JulyKill

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

Download Current DAT: 6712

Threat Detail

Malware Type: Virus

Malware Sub-type: Macro

Discovery Date: 1999-06-16

Next Steps:

Overview
Characteristics
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

4033 (1999-07-07)

Updated DAT

4033 (1999-07-07)

Minimum Engine

5.1.00

File Length

Description Added

1999-06-19

Description Modified

2002-08-02

Malware Proliferation

Characteristics

This is a virus for Word 97 documents. It is not able to replicate under the SR-1 release of Word 97. Upgrading to the SR-1 release of Word 97 or later will stop it from spreading. It may only be able to spread under the Taiwanese version of Word. This macro virus will infect Word's normal.dot file. It will create an infected file called c:\autoexec.dot and set Word to load templates from C:\ so Autoexec.dot is loaded when Word starts. This is a stealth virus; it will attempt to intercept the macro viewing commands to attempt to hide its presence. This virus consists of a module called a. It will turn off the macro warning feature of Word. In July, it will display a dialog box in Taiwanese(?) If the user enters the correct response, (OK Button) it says "You are wise, please choose this later again, critically!"

If the user enters the incorrect response (Cancel Button) it says
"Stop it! you are so incurable to lose 3 chances!"
"Now,god will punish you..."
Then it overwrites "C:\autoexec.bat" with "deltree/y c:\"

Symptoms

Method of Infection

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.