Abstract: A regularization unit standardizes similar expressions across a plurality of URIs in access logs of requests made to a plurality of web servers, thereby changing the URIs into regularized URIs. A calculation unit calculates, among the access logs that are from the same source, the relative frequency of certain access logs to all access logs, the certain access logs corresponding to requests made to different destinations for the same regularized URI and also corresponding to certain response codes. If the largest of all the relative frequencies calculated for the regularized URIs is at least a certain threshold, a determination unit determines the regularized URIs to be scanning targets.

Abstract: An estimation unit (136) retrieves a subtree that matches a query to be estimated, from subtrees included in a syntax tree created from a query inserted into a Web request. In addition, the estimation unit (136) presents information for specifying the type of damage of an attack and an attack target, the information being associated in advance with the subtree obtained by the retrieval of the retrieval unit. An estimation unit retrieves a subtree that matches a query to be estimated, from subtrees included in a syntax tree created from a query inserted into a Web request. In addition, the estimation unit presents information for specifying the type of damage of an attack and an attack target, the information being associated in advance with the subtree obtained by the retrieval of the retrieval unit.

Abstract: A regularization unit standardizes similar expressions across a plurality of URIs in access logs of requests made to a plurality of web servers, thereby changing the URIs into regularized URIs. A calculation unit calculates, among the access logs that are from the same source, the relative frequency of certain access logs to all access logs, the certain access logs corresponding to requests made to different destinations for the same regularized URI and also corresponding to certain response codes. If the largest of all the relative frequencies calculated for the regularized URIs is at least a certain threshold, a determination unit determines the regularized URIs to be scanning targets.