alert tcp-pkt $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Winos4.0 Framework CnC Login Message CnC Server Response"; flow:established,to_client; flowbits:isset,ET.Winos4.Login; dsize:14<>128; byte_jump:4,0,little, post_offset -5; isdataat:!2,relative; content:"|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:2059975; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state plaintext, created_at 2025_02_07, deployment Perimeter, malware_family Winos4_0, confidence High, signature_severity Critical, tag c2, updated_at 2025_03_03, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1573, mitre_technique_name Encrypted_Channel; target:src_ip;)