alert tcp-pkt $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Winos4.0 Framework CnC Login Message"; flow:established,to_server; flowbits:set,ET.Winos4.Login; dsize:14<>64; byte_jump:4,0,little, post_offset -5; isdataat:!2,relative; content:"|00 00 00 00 00 ca|"; depth:13; fast_pattern; pcre:"/^(?:\x00|\x01)/R"; threshold:type limit, count 1, seconds 60, track by_src; reference:md5,db9fd417244157770e31fb4b39e0e97a; reference:url,fortinet.com/blog/threat-research/threat-campaign-spreads-winos4-through-game-application; classtype:command-and-control; sid:2052875; rev:7; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, attack_target Client_and_Server, tls_state plaintext, created_at 2024_05_23, deployment Perimeter, deployment SSLDecrypt, malware_family Winos4_0, performance_impact Low, confidence High, signature_severity Critical, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_09_29, reviewed_at 2024_10_04; target:src_ip;)