A method for identifying a program copy by means of digital watermark is presented in this article. Previously known analogues for constructing a watermark used modification of program's control flow graph, and reading was made via complex analysis of the program's trace. It is known that applying a protector or packer can neutralize such a watermark. In this paper, it is proposed to use a multi-threaded application that generates numbers with a normal distribution law. The embedding of the digital watermark is carried out by changing the dispersion of distributions. Such random variable can be found via a signature in the process memory and is used both within the program itself and by a third-party when reading the watermark. An experimental selection of the optimal parameters of the algorithm has been carried out. Overhead expenses associated with the creation of a large number of threads are estimated.