Abstract: Against the unstructured attack, this paper proposes a model of social engineering based on objective manage- ment,and innovative use of the target model simulates the attack process put forwarded by the former Soviet world chess champion Garry Kasparov. A complete system of social engineering attacks and means of achieving are abstracted for the first time and factors extraction and threats assessment arc used towards such unstructured attack process to es- tablish the mathematical model and conclude the social engineering risk value. Combined with a large number of real case of enterprises, the model can evaluate the security posture of the system and organization before the social engi- necring attacks, and provides reliable data support to prevent such attacks so as to eradicate them.

Key words: Social engineering, Objective management, Factors extraction, Threat assessment, Social engineering risk