alert http $EXTERNAL_NET any -> $HOME_NET $HTTP_PORTS (msg:"ET SCAN Yandex Webcrawler User-Agent (YandexBot)"; flow:established,to_server; http.user_agent; content:"YandexBot"; nocase; classtype:not-suspicious; sid:2032979; rev:2; metadata:attack_target Web_Server, created_at 2021_05_18, deployment Perimeter, confidence High, signature_severity Informational, tag WebCrawler, updated_at 2022_05_03, mitre_tactic_id TA0043, mitre_tactic_name Reconnaissance, mitre_technique_id T1593, mitre_technique_name Search_Open_Websites;)