obtained the threshold of time delay when Hopf bifurcation occurred. Considering the fact that the intrusion detection system (IDS) may lead to time delay, Yao et al. Some research achievements showed that the spread dynamic system of malware would be unstable and bifurcation and chaos would appear. Then many mathematical models inspired by the SIR model have been employed to constrain the propagation of Internet worms. Qing and Wen introduced the Kermack-McKendrick model, which is also called SIR model. In order to study the spread of malware among mobile phones, the SIS model is proposed by some researchers.
#New worm virus 2012 code#
Some traditional epidemic models of infectious diseases were used to describe the propagation of Internet worms when the Red Code worms broke out.
![new worm virus 2012 new worm virus 2012](https://assets.rbl.ms/25571945/origin.jpg)
Consequently, many experts focus on the spread of Internet worms. Meanwhile, the characteristics of worm attacks are wide infection scale, fast spread speed, and serious harm.
![new worm virus 2012 new worm virus 2012](https://th-thumbnailer.cdn-si-edu.com/BPk_nug7NuxIVwRaJ2-VZ-4LJqc=/1000x750/filters:no_upscale()/https://tf-cmsv2-smithsonianmag-media.s3.amazonaws.com/filer/top-10-computer-viruses-631.jpg)
Among the security events, the consequences of large-scale network attacks (such as worm attacks and DOS attacks) are especially serious. With the deep application of the Internet, network security plays a more and more important role in recent years. Finally, simulation experiments are carried out to prove the validity of our conclusions. The numerical experiments also show that there exists a threshold in the parameter, which implies that we should choose appropriate infection rate to constrain worm prevalence. In addition, numerical experiments have been performed, which can match the conclusions we deduce. When time delay is over, the system will be unstable. The worm propagation system is stable if time delay is less than. Moreover, the threshold of Hopf bifurcation is obtained. Due to the existence of time delay, the worm propagation system may be unstable and out of control. Then the existence condition and the stability of the positive equilibrium are derived. According to above aspects, we propose a time-delayed worm propagation model with variable infection rate. Considering the actual situation, a variable infection rate is introduced to describe the spread process of worms. On the other hand, the worm infection is usually a nonlinear process. This leads to a time delay when vaccinated hosts change to susceptible hosts.
![new worm virus 2012 new worm virus 2012](https://images.slideplayer.com/20/6216942/slides/slide_3.jpg)
Temporary patches have been put on the infectious hosts, which may lose efficacy on occasions. With rapid development of Internet, network security issues become increasingly serious.