alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE DcRAT/Sheet RAT CnC Checkin Using MessagePack"; flow:established,to_server; byte_jump:4,0,little,from_beginning, post_offset 3; isdataat:!2,relative; content:"|1f 8b 08|"; offset:8; depth:3; fast_pattern; reference:md5,ea908652fb0c5618cfa74f6bf49b6363; reference:url,github.com/qwqdanchun/DcRat/blob/main/MessagePack/MessagePack/Zip.cs; classtype:trojan-activity; sid:2058998; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, affected_product Windows_8, affected_product Windows_10, attack_target Client_Endpoint, tls_state plaintext, created_at 2025_01_06, deployment Perimeter, malware_family DCRat, malware_family Sheet_RAT, performance_impact Significant, confidence High, signature_severity Major, updated_at 2025_01_06, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel; target:src_ip;)