alert tcp $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"ET SCAN SQLNinja MSSQL Version Scan"; flow:to_server,established; content:"?param=a"; content:"if%20not%28substring%28%28select%20%40%40version"; distance:2; reference:url,sqlninja.sourceforge.net/index.html; classtype:attempted-recon; sid:2009038; rev:4; metadata:created_at 2010_07_30, confidence Medium, signature_severity Informational, updated_at 2019_07_26;)