alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Win32.Raccoon Stealer Checkin Response M4"; flow:established,to_client; file_data; content:"2HVWm7UNyz"; startswith; fast_pattern; pcre:"/^[a-zA-Z0-9+\/]+(?:[a-zA-Z0-9+\/]{2}==|[a-zA-Z0-9+\/]{3}=|[a-zA-Z0-9+\/]{4})$/"; reference:md5,108757a3cc9c5e9d529ca1a94f1432b2; classtype:command-and-control; sid:2035178; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_02_11, deployment Perimeter, deployment SSLDecrypt, malware_family Raccoon_Stealer, performance_impact Moderate, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_02_11;)