alert http $EXTERNAL_NET any -> any any (msg:"ET MALWARE ELF/Mirai Variant UA Inbound (muhstik)"; flow:established,to_server; http.user_agent; content:"muhstik"; nocase; depth:7; pcre:"/^muhstik(?:-scan)?(?:\/[0-9]\.0)?$/i"; classtype:trojan-activity; sid:2027138; rev:3; metadata:affected_product Linux, attack_target IoT, created_at 2019_03_27, deployment Perimeter, malware_family Mirai, performance_impact Low, confidence High, signature_severity Minor, updated_at 2020_10_23;)