alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Fujacks Variant CnC Activity"; flow:established,to_server; http.start; content:"GET /down1.txt HTTP/1.1|0d 0a|User-Agent|3a 20|ErrCode|0d 0a|Host|3a 20|"; startswith; http.header_names; content:!"|0d 0a|Referer|0d 0a|"; content:!"|0d 0a|Connection|0d 0a|"; content:!"|0d 0a|Accept|0d 0a|"; reference:md5,54b72be155b057f693508c0d15fc6d00; classtype:command-and-control; sid:2030580; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_07_22, deployment Perimeter, malware_family Win32_Fujacks, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_07_22;)