This is not really a virus, but a "add-on" product supplied by the person
who calls himself Dark Avenger. It can be used to give any virus a
"polymorphic" ability, making it undetectable with a signature-based
scanner.
Instead an algorithmic approach is used, which may (theoretically)
produce false alarms. So, if F-Secure anti-virus products ever
report a single file as containing MtE, don't be too alarmed - it
might just be a false positive. If you get an alarm from a data file
(non-executable), it's a certain false positive. Send a sample and
we'll fix it.
One known false alarm is a file called 120492_v.dxf. If you find
MtE from this file, simply ignore it.
Another known false alarms is from a data file called bf1g2.acm.
This file is from a game called Baldur's Gate. If you find MtE
from this file, simply ignore the false alarm. We are working
to fix this.
Several viruses are known to make use of this Mutation Engine:
Those two viruses are almost identical - but with different text messages.
They would be considered totally unremarkable, if not for the inclusion of
the engine.
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