alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE TA397/Bitter Requesting Next Stage Payload"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/"; pcre:"/^[a-z]+\.php\?[a-z]+=[\w\-]+_[\w\-]+$/R"; http.user_agent; content:"curl|2f|"; startswith; fast_pattern; http.header_names; to_lowercase; content:!"referer|0d 0a|"; content:!"|0d 0a|accept-"; classtype:command-and-control; sid:2058192; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2024_11_26, deployment Perimeter, malware_family Bitter, performance_impact Significant, confidence High, signature_severity Major, updated_at 2025_02_03, former_sid 2859194; target:dest_ip;)