Autonomic systems exhibit the ability of self-monitoring, self-repairing, and self-optimizing by constantly sensing themselves and tuningtheir performance. The notions of autonomic components (ACs) and autonomic-component ensembles (ACEs) are considered in the paper. A languagefor coordinating ensemble components (SCEL) is used to represent specificity of security issues in autonomic computing environment. Toreveal abnormal behavior of ACEs the information theory metric (in particular, Kullback –Leibler divergence) is proposed to use in the approachdescribed in the paper.