alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Marco Stealer Data Exfiltration Attempt"; flow:established,to_server; http.method; content:"POST"; http.uri; bsize:8; content:"/receive"; http.user_agent; bsize:10; content:"DataSenter"; fast_pattern; http.header_names; content:!"|0d 0a|referer|0d 0a|"; http.request_body; content:"data|3d|"; startswith; pcre:"/^[a-f0-9]{10,}/R"; reference:url,www.zscaler.com/blogs/security-research/technical-analysis-marco-stealer; classtype:trojan-activity; sid:2067367; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, attack_target Client_Endpoint, tls_state plaintext, created_at 2026_02_06, deployment Perimeter, malware_family Stealer, malware_family MarcoStealer, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2026_02_06, mitre_tactic_id TA0009, mitre_tactic_name Collection, mitre_technique_id T1005, mitre_technique_name Data_from_local_system; target:src_ip;)