| 摘要 |
PROBLEM TO BE SOLVED: To attain collection on the basis of a predefined index of a URL that is suspected to be a harmful site, and to efficiently update an internal database of a URL filter.SOLUTION: Communication devices 1 and 8 provided with a relay process part 5 or a Web browser 7 that interconnects a local area network (LAN) and a wide area network (WAN) comprise: monitoring parts 10 and 31 that monitor a first request for starting viewing of a Web resource and a second request for ending the viewing of the Web resource, calculate a lapsed time from the first request to the second request and detect URL in which the lapsed time becomes less than a threshold value; and a notification part 11 that transmits the URL detected by the monitoring parts 10 and 31 to a predetermined node 3. The node 3 has a suspected URL management part 12 that stores the received URL and counts the number of receptions for each URL, and a harmful site detection part 4 targets the URL for analysis in descending order of the number of receptions, of the URLs stored in the suspected URL management part 12. |
