alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Foudre Checkin M2"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/201"; depth:4; content:"/?c="; distance:1; within:4; fast_pattern; content:"&u="; distance:0; content:"&v="; distance:0; content:"&s="; distance:0; content:"&f="; distance:0; content:"&mi="; distance:0; content:"&b="; distance:0; content:"&t="; distance:0; http.host; pcre:"/^[a-f0-9]{8}\.(?:s(?:pac|it)e|net|top)$/"; http.header_names; content:!"Referer|0d 0a|"; reference:url,researchcenter.paloaltonetworks.com/2017/08/unit42-prince-persia-ride-lightning-infy-returns-foudre/; classtype:command-and-control; sid:2031410; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_08_02, deployment Perimeter, performance_impact Moderate, confidence High, signature_severity Major, updated_at 2020_08_11;)