alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE W32/Patchwork.Backdoor CnC Check-in M2"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php?b="; nocase; pcre:"/^[A-F0-9]{30}$/Ri"; http.content_len; byte_test:0,=,0,0,string,dec; reference:md5,ddeabe234c4084ba379cf3be4fdf503d; classtype:command-and-control; sid:2025164; rev:5; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_12_21, deployment Perimeter, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_11_09;)