alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE GlassWorm Decryption IV/Key Response"; flow:established,to_client; http.header; content:"ivbase64|3a 20|"; fast_pattern; nocase; content:"secretkey|3a 20|"; nocase; reference:url,www.koi.ai/blog/glassworm-first-self-propagating-worm-using-invisible-code-hits-openvsx-marketplace; classtype:trojan-activity; sid:2065256; rev:1; metadata:attack_target Client_Endpoint, created_at 2025_10_20, deployment Perimeter, confidence High, signature_severity Major, tag c2, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_10_20, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)