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Discrete Dynamics in Nature and Society
Volume 2012 (2012), Article ID 693695, 13 pages
Research Article

Propagation Behavior of Virus Codes in the Situation That Infected Computers Are Connected to the Internet with Positive Probability

1College of Computer Science, Chongqing University, Chongqing 400044, China
2School of Electronic and Information Engineering, Southwest University, Chongqing 400716, China

Received 23 May 2012; Accepted 4 June 2012

Academic Editor: Yanbing Liu

Copyright © 2012 Lu-Xing Yang and Xiaofan Yang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


All the known models describing the propagation of virus codes were based on the assumption that a computer is uninfected at the time it is being connected to the Internet. In reality, however, it is much likely that infected computers are connected to the Internet. This paper is intended to investigate the propagation behavior of virus programs provided infected computers are connected to the Internet with positive probability. For that purpose, a new model characterizing the spread of computer virus is proposed. Theoretical analysis of this model indicates that (1) there is a unique (viral) equilibrium, and (2) this equilibrium is globally asymptotically stable. Further study shows that, by taking active measures, the percentage of infected computers can be made below an acceptable threshold value.