Virus Profile: W97M/Caligula.a

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Virus Profile information details
Risk Assessment: Home Low | Corporate Low
Date Discovered: 3/1/1998
Date Added: 2/1/1999
Origin: N/A
Length: N/A
Type: Virus
Subtype: Macro
DAT Required: 4012
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

Methods of Infection



Virus Characteristics

This is a newly discovered Word97 macro virus which uses an export to file/import from file method of infection. The hosting file for the virus code is 'c:\io.vxd'.

This virus uses an AUTOCLOSE macro, with a module name of CALIGULA

This virus modifies documents/templates infected with these properties-

Author: 'Opic'
Title: 'WM97/Caligula Infection'
Subject: 'A Study In Espionage Enabled Viruses.'
Comments: 'The Best Security Is Knowing The Other Guy Hasn't Got Any.'
Keywords: ' | Caligula | Opic | CodeBreakers | '

disables macro warning, prompt to save, confirmation to convert

disables ToolsMacro, VB Editor

disables menu items ToolsMacro, ToolsCustomize, ViewToolbars

on the 31st of month displays message box.

If user name is not 'Caligula', runs PGP Secure Keyring find and send routine - user name retrieved from registry

'HKCU\Software\Microsoft\MS Setup (ACME)\User Info'

Searches for PGP Secure Keyring using registry entry to get PGP installed path

If key does not exist, exits otherwise searches for 'Secring.skr' in PGP path

If file found, file is uploaded to the virus author's ftp site using a script file written as 'c:\cdbrk.vxd' and using ftp.exe in a hidden process

The computer user name is set to 'Caligula'

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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