alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE [ANY.RUN] Win32/Stealc Checkin (POST)"; flow:established,to_server; http.method; content:"POST"; http.content_type; content:"multipart|2f|form|2d|data|3b 20|boundary|3d|"; startswith; pcre:"/^[a-zA-Z0-9]{20}$/R"; http.header_names; content:!"Referer"; http.host; pcre:"/^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$/"; http.request_body; content:"|2d 2d|"; depth:2; content:"Content|2d|Disposition|3a 20|form|2d|data|3b 20|name|3d 22|hwid|22|"; fast_pattern; content:"Content|2d|Disposition|3a 20|form|2d|data|3b 20|name|3d 22|build|22|"; threshold:type limit, track by_dst, seconds 300, count 1; reference:md5,26f5d78873413d9682031d39733ae5bd; reference:url,app.any.run/tasks/a9908b18-0302-4d20-8349-6aca4db61e98; reference:url,community.emergingthreats.net/t/stealc-stealer/856; classtype:trojan-activity; sid:2047625; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_08_11, deployment Perimeter, deployment SSLDecrypt, malware_family Stealc, performance_impact Low, confidence High, signature_severity Critical, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_12_28; target:src_ip;)