alert tcp $EXTERNAL_NET any -> $HOME_NET $HTTP_PORTS (msg:"ET WEB_SPECIFIC_APPS phpBB3 Brute-Force reg attempt (Bad pf_XXXXX)"; flowbits:isset,ET.phpBB3_test; flow:to_server,established; content:"POST "; depth:5; nocase; content:"/ucp.php"; http_uri; nocase; content:"mode=register"; http_uri; content:"username="; content:"email="; content:"pf_XXXXX="; pcre:!"/^YYY$/R"; flowbits:unset,ET.phpBB3_test; classtype:web-application-attack; sid:2010895; rev:3; metadata:created_at 2010_07_30, signature_severity Major, updated_at 2019_08_22;)