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-
- Attached is a recent report off the Internet on the Mutating Engine:
- Part 1/4
- *************************************
-
-
- -----------------------------------------------------------------------
- 22 Jun 92
-
- Mutation Engine Report
-
-
- Copyright (c) 1992 by VDS Advanced Research Group
- All Rights Reserved
-
- P.O. Box 9393
- Baltimore, MD 21228
- (410) 247-7117
-
- prepared by
-
- Tarkan Yetiser
-
-
- This report is provided to satisfy the curiosity of the
- public. We were approached by some third parties to perform an
- analysis on MtE. We would like to share the results of our
- analysis with everyone. If you find an error or inaccuracy in
- this report, please feel free to contact us. All constructive
- criticism is welcome.
-
-
- TABLE of CONTENTS
-
- I. Mutation Engine and Viruses. . . . . . . . . . . . . . . . . . . 1
-
- II. How to Catch Viruses and MtE-based Viruses . . . . . . . . . . 2
-
- III. Mutation Types and Detection Algorithms. . . . . . . . . . . . 3
-
- IV. Live Tests and Results . . . . . . . . . . . . . . . . . . . . 5
- A. Comments on Test Results . . . . . . . . . . . . . . . 5
-
- V. A Simple Message . . . . . . . . . . . . . . . . . . . . . . . 6
-
-
- I. Mutation Engine and Viruses
-
- We have analyzed the so-called MtE (Mutation Engine by a "Dark
- Avenger" from Bulgaria), and sample viruses based on it; namely,
- Pogue and Dedicated. We have also conducted tests to examine what
- kind of a potential this miscreant has, and collected empirical
- data on how popular scanners deal with the MtE. We have also implemented a
- little program (CatchMTE) that can recognize MtE-based code using an
- algorithmic technique. The program in executable form is available free of
- charge as a service to the public. Due to possible misuse, the source code
- and a more detailed (at the opcode and bit-mask level) analysis with
- decryptor samples and algorithms necessary to detect MtE will be made
- available in a limited fashion. Under no circumstances, actual virus
- samples will be provided; except the missed samples can be sent to known
- anti-viral product developers who wish to enhance their programs.
-
- For those who are not familiar with the MtE, some preliminary
- info will be presented first:
-
- MtE is NOT a virus per se, but an object module that can be
- linked into a virus to give it polymorphic capabilities. MtE
- expects to be called as a routine that can encrypt a certain
- portion of code and can generate a suitable decryption routine. It
- uses a random number generator to vary each mutation so that it
- will not be possible to recognize the new variant by using simple
- scanning techniques. The random number generator is not part of the
- MtE object module. A sample pseudo-random number generator is
- included with the archive Dark Avenger distributes. A virus writer
- could also supply his own random number generator.
-
- TO BE CONTINUED ....
-