@techreport{oai:ipsj.ixsq.nii.ac.jp:00178514, author = {榊原, 裕之 and 岩崎, 亜衣子 and 河内, 清人 and Hiroyuki, Sakakibara and Aiko, Iwasaki and Kiyoto, Kawauchi}, issue = {29}, month = {Feb}, note = {近年,化学プラントなど重要インフラへの攻撃が懸念されている.重要インフラにおける機器の保守端末は,攻撃者により侵害されると機器に不正な設定が行われ,誤動作し事故の原因となりうるため,セキュリティ対策の強化が必要である.セキュリティ対策として,アンチマルウエア等セキュリティ対策ソフトウエアの導入に加えて,保守端末のイベントログを分析し不審な事象を検知する方法がある.しかし,ログの分析方法によっては,保守端末における操作誤りなどを攻撃として誤検知してしまう課題がある.本稿では,この課題について,保守作業の計画情報を参照し,検知の原因が保守によるものか否かを判定する方法を提案し,その効果について考察する.また,イベントログにおいて,シナリオに沿った複数の攻撃と思われる事象を検知することで,誤検知を低減する方法についても考察する., In recent years, attacks on critical infrastructures such as chemical plants are concerned. When an equipment maintenance terminal in a critical infrastructure is attacked by an attacker, the attacker will set unwanted configuration to equipments, which causes a malfuction of a control system and leads to an accident. Therefore, security enhancement of an equipment maintenance terminal is important. As security masures, in addition to security products such as anti-malware, analyzing an event log of an equipment maintenance terminal is conceivable. However, depending on log anlyzing methods, events on an event log caused by misoperations on an equipment maintenance terminal would be detected as attacks. In this paper, as a solution to the issue, a method which decides suspcius events on an eventlog is caused by maintenance or an attack reffering to a maintenance plan is proposed. In addition, we discuss a log analysis method which detects multiple events on a event log following an attack senario to detemine the events are caused by an attack or not.}, title = {作業情報等に基づく重要インフラのサイバー攻撃検知について}, year = {2017} }