When the virus activates in Word, it will first check if the global
template is already infected. If this is not the case, it will disable
the built-in macro virus protection for both Excel and Word. It does
not, however, disable macro virus protection for PowerPoint. The virus
also removes all the existing macros from the Word's global template.
Then it performs a check if there is a file named "Book1." at the
Excel's startup directory. If the file is present, it assumes that
Excel is already infected, but if the file is not present it launches
Excel and saves an infected worksheet to the startup directory.
Finally it attempts to infect the "Blank Presentation" template in
PowerPoint. The virus will launch PowerPoint and check if it is
already infected by checking the existence of the module named
"Triplicate". If the module is not found it will add an invisible
shape to the first slide and copies itself to the template.
The infection process is similar in all three applications while the
activation differs in every application. In Word it will activate when
a document is closed as mentioned above. In Excel it activates when
the infected workbook is deactivated and in PowerPoint there is a 1/7
chance that it will activate when the invisible shape is clicked with
This virus does not have a payload but it will intentionally remove
all macros from Word's global template.
The following text is visible in all infected documents:
Triplicate v0.1 /1nternal
This variant almost indentical with O97M/Tristate.A. There is some
minor modifications in the virus code and the visible text has been
Triplicate v0.21 /1nternal
This variant slightly modified from O97M/Tristate.A, and the text in
the virus code has been changed to:
Triplicate v0.2 /1nternal
O97M/Tristate.F is partially modified variant of O97M/Tristate.C. The
modification causes that this variant is unable to infect PowerPoint
from Excel. However, the infection of Excel is functional from Word.
O97M/Tristate.H is a slightly modified variant from O97M/Tristate.C.
This variant infects the global template every time when an infected
document is closed, regardless of its contents.
O97M/Tristate.I is functionally identical with O97M/Tristate.C.
O97M/Tristate.L is functionally identical with O97M/Tristate.C.
O97M/Tristate.W is functionally identical with O97M/Tristate.C.
O97M/Tristate.X is almost identical with O97M/Tristate.C, except
instead of disabling the built-in macro virus protection it enables
This variant is functionally identical with O97M/Tristate.C.
This is a slightly modified variant of O97M/Tristate.F.
This is a corrupted variant of O97M/Tristate. Due the corruption, this
variant is able to replicate only within PowerPoint.
[Analysis: Sami Rautiainen, F-Secure]