An automatic unpacking method for computer virus effective in the virus filter based on Bayesian theorem

一种基于静态代码分析的快速自动病毒检测算法是非常必要的，然而，目前的计算机病毒大多被压缩成可执行的压缩格式，并且被混淆，因此很难从混淆的计算机病毒中确定二进制代码的特征。提出了一种不受压缩类型限制的计算机病毒自动解包方法，该方法与现有的贝叶斯病毒过滤器等已知病毒检测系统相结合，可以有效地检测未知病毒，检测率达到95%，误检率为0.02%.

A rapid automatic virus detection algorithm using static code analysis is necessary.However,recent computer viruses are almost compressed into the executable compress format and are obfuscated.Thus,it is difficult to determine the characteristics of the binary code from the obfuscated computer viruses.In this research,a method that unpacks compressed computer viruses automatically without restriction to compression type is proposed.The proposed method unpacks the common compression formats accurately 80% of the time,while unknown compression formats can also be unpacked.The proposed method is effective against unknown viruses by combining it with the existing known virus detection system like Bayesian Virus Filter.We could achieve to implement 95% detection rates and 0.02% false detection rates.