alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE GCleaner Downloader - Payload Response"; flow:established,to_client; http.content_type; bsize:24; content:"application/octet-stream"; http.response_header; header_lowercase; content:"content-transfer-encoding|3a 20|binary"; startswith; http.response_header; content:"content-disposition|3a 20|attachment|3b 20|filename|3d 22|"; startswith; content:"dllENCR.dll|22 3b|"; fast_pattern; endswith; reference:md5,780099266c4cf79fbf344297b0a4e29e; classtype:trojan-activity; sid:2044037; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_12_06, deployment Perimeter, malware_family GCleaner, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_05_04, former_sid 2852925;)