alert tcp $HOME_NET any -> $EXTERNAL_NET 1024: (msg:"ET MALWARE MSIL/Firebird RAT CnC Checkin"; flow:established,to_server; dsize:<100; content:"|01 00 00 00 ff ff ff ff 01 00 00 00 00 00 00 00 06 01 00 00 00|"; depth:22; fast_pattern; content:"|0b|"; endswith; reference:md5,ede8ebfc82463d1e7e6f29ca66f96514; classtype:command-and-control; sid:2029606; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_03_11, deployment Perimeter, malware_family Firebird, confidence High, signature_severity Major, updated_at 2022_07_21, reviewed_at 2024_04_30;)