alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE TA422 Related Activity M3"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/filedwn.php?id="; startswith; fast_pattern; pcre:"/^[a-f0-9]{8}-(?:[a-f0-9]{4}-){3}[a-f0-9]{12}/R"; flowbits:set,ET.TA422.Mockingbird; classtype:trojan-activity; sid:2049286; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, attack_target Client_Endpoint, created_at 2023_11_16, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_11_22, reviewed_at 2025_07_14, former_sid 2855826; target:src_ip;)