alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE TA398 CurlBack_RAT CnC Activity - Upload Results"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"|2f|stluser"; startswith; fast_pattern; threshold:type limit, track by_src, seconds 300, count 1; reference:url,www.seqrite.com/blog/goodbye-hta-hello-msi-new-ttps-and-clusters-of-an-apt-driven-by-multi-platform-attacks/; classtype:trojan-activity; sid:2065650; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2025_11_05, deployment Perimeter, confidence High, signature_severity Major, tag TA398, tag Description_Generated_By_Proofpoint_Nexus, tag CurlBack_RAT, updated_at 2025_11_12, mitre_tactic_id TA0037, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)