alert http $EXTERNAL_NET any -> $HTTP_SERVERS any (msg:"ET SCAN Acunetix Version 6 Crawl/Scan Detected"; flow:to_server,established; threshold:type threshold, track by_dst, count 2, seconds 5; http.uri; content:"/acunetix-wvs-test-for-some-inexistent-file"; reference:url,www.acunetix.com/; classtype:attempted-recon; sid:2008571; rev:8; metadata:created_at 2010_07_30, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_09_14;)