Abstract
Due to the widespread dissemination of informational distributed computing networks reveals problems in information protection from unauthorized access. This article deals with the security problem of informational computer networks from network informational attacks. Revealed in the article stages of unauthorized access to computing informational network, showed that even the protected computing system acquires certain vulnerability when it is connected to the public network. Have been described the characteristics of protection against network attacks. The proposed specifications are of good quality and are expressed requirements to ensure the resistance of certain offender actions. The proposed model of offender actions gives more accurately determine the list of threats, which must be taken into account in the designing of data protection and in security policy of an informational computing network. Considered characteristics give possibility to assess security of the distributed informational computing networks, which consist of geographically dispersed components of various network informational attacks.