alert tcp $EXTERNAL_NET any -> $HOME_NET $HTTP_PORTS (msg:"ET DOS HTTP GET AAAAAAAA Likely FireFlood"; flow:to_server,established; content:"GET AAAAAAAA HTTP/1.1"; content:!"Referer|3a|"; distance:0; content:!"Accept"; distance:0; content:!"|0d 0a|"; distance:0; threshold:type both,track by_dst,count 500,seconds 60; classtype:attempted-dos; sid:2019347; rev:2; metadata:created_at 2014_10_03, confidence Medium, signature_severity Major, updated_at 2019_07_26;)