Software tampering detection system and network security system

摘要

PROBLEM TO BE SOLVED: To provide a system that can detect even the presence of malware integrated into firmware on a hard disk of a computer.SOLUTION: A computer security system 2 includes: a portable storage medium 12 for storing a dedicated OS 54 that controls a main unit 10; and a center device 6 for communicating with a user terminal device 4 during inspection. At the time of inspection, the user terminal 4 is activated by the dedicated OS 54 of the connected portable storage medium 12. A hash value calculation program 56 in the portable storage medium 12 generates a hash value for firmware of an HDD 32, and transmits it to the center device 6. The center device 6 receives hash values from a plurality of user terminal devices 4, determines whether each of the hash values is normal or abnormal according to the frequency of each hash value, and notifies a user terminal device 4 that transmitted a low-frequency hash value determined to be abnormal of the detection of alteration.SELECTED DRAWING: Figure 1