alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE [PTsecurity] Win32/Ramnit Stage 0 Communicating with CnC"; flow:established,to_client; http.stat_code; content:"200"; file.data; content:"WAIT|20|"; depth:15; content:"CERT|20|"; fast_pattern; within:20; pcre:"/^(?:[A-Z0-9+/]{4})*(?:[A-Z0-9+/]{2}==|[A-Z0-9+/]{3}=|[A-Z0-9+/]{4})/Ri"; reference:md5,20148e48668cb5e0b22d437ee0443cfe; reference:url,research.checkpoint.com/ramnits-network-proxy-servers/; classtype:command-and-control; sid:2026113; rev:5; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2018_09_14, deployment Perimeter, malware_family Ramnit, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_11_18;)