Information technology systems represent the backbone of a company's operational infrastructure. A company's top management typically ensures that computer software and hardware mechanisms are adequate, functional and in adherence with regulatory guidelines and industry practices. Nowadays, due to depressed economic and increased intensity of performed operations, business highly recognizes the influence of effective Information Technology risk management on profitability. Described in this paper design of Unified Modelling Language (UML) based Domain Specific language (DSL) achieves synergy from in IT industry widely used UML modelling technique and the domain specific risk management extensions. As a novelty for UML modelling, especially for simulation purposes, the presented DSL is enriched by a set of stochastic attributes of modelled activities. Such stochastic attributes are usable for further implementation of discrete-event system simulators.