在防动态跟踪的多种技术中,指令覆盖法显得更为隐蔽,它在程序的执行过程中IP保持不变。从而使指令在同一地址上叠加运行,同时,指令的执行方向是逆向的。它在逆指令技术上的一个改进,克服了原来逆指令中不能回跳的问题,同时也达到了有效防止解密者动态跟踪和静态分析的目的。本文目的是介绍其具体实现方法及原理。 Among the many techniques that prevent dynamic tracking, instruction overlay appears to be more subtle and maintains its IP during program execution. So that instructions at the same address overlay operation, at the same time, the direction of the instruction is reverse. It is an improvement on the counter-instruction technique, which overcomes the problem that the original counter-instruction can not jump-back. At the same time, it also achieves the purpose of effectively preventing the dynamic tracking and static analysis of the decrypter. The purpose of this paper is to introduce its specific implementation methods and principles.