Currently the use of bots, i.e., auto-accounts in social networks which are managed with special programs but disguised as ordinary users, has serious consequences. For example, bots have been used to influence political elections, distort information on the Internet and manipulate prices on the stock exchange. Many research teams concerned with the detection of such accounts have made use of machine learning methods. However, the practical results of detecting social network bots indicate significant limitations because the methodological tools used have language limitation and ineffective criteria for detection. This article presents improved countermeasures in a methodological approach to develop a universal social network account classifier for minimizing the average risk of errors in bot detection. The application of an assembly of classifiers united by a data adaptation criterion and results from the variance of each model found the formation of a universal classifier for social network accounts. The main results obtained by the authors consist of the criteria system and the categorical (nominal) features transformation approach for the formation of the special ensemble of classifiers. In practice, use of the ensemble of classifiers allows us to increase the effectiveness of bot detection compared to other approaches.