alert http $EXTERNAL_NET any -> any any (msg:"ET EXPLOIT Barracuda Spam Firewall 3.3.x RCE 2006-4000 (Inbound)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/cgi-bin/preview_email.cgi?file=/mail/mlog/|7c|"; depth:44; fast_pattern; content:"http"; distance:0; reference:url,unit42.paloaltonetworks.com/mirai-variant-echobot-resurfaces-with-13-previously-unexploited-vulnerabilities/; reference:cve,2006-4000; classtype:attempted-admin; sid:2029173; rev:2; metadata:affected_product Linux, attack_target IoT, created_at 2019_12_16, cve CVE_2006_4000, deployment Perimeter, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_26;)