alert tcp-pkt $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE PackClient RAT Payload Request - C2 Response"; flow:established,to_client; flowbits:isset,ET.PackClient_RAT.Payload; dsize:64; content:"|40 5a 15 00 00 00|PLK1"; depth:12; fast_pattern; byte_jump:2,0,from_beginning,little,post_offset 3; isdataat:!2,relative; reference:md5,c55f9bc3c53ac32e6169ad3cc8b2ce49; classtype:trojan-activity; sid:2069882; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, attack_target Client_Endpoint, tls_state plaintext, created_at 2026_06_10, deployment Perimeter, malware_family PackClient_RAT, performance_impact Low, confidence High, signature_severity Major, tag RAT, updated_at 2026_06_10;)