alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Backdoor family PCRat/Gh0st CnC traffic (OUTBOUND) 101"; flow:established,to_server; app-layer-protocol:!tls; stream_size:server,<,5; dsize:>11; content:"|71 9e|"; offset:8; byte_jump:4,-10,relative,little,from_beginning,post_offset -1; isdataat:!2,relative; pcre:"/^[\x20-\x7e]+?.{8}\x71\x9e/s"; reference:url,www.microsoft.com/security/portal/Threat/Encyclopedia/Entry.aspx?Name=Backdoor%3AWin32/PcClient.ZR&ThreatID=-2147325231; reference:md5,8776e617b59da52bcac43b380a354aa0; classtype:command-and-control; sid:2021065; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state plaintext, created_at 2015_05_07, deployment Perimeter, malware_family Gh0st, malware_family PCRAT, performance_impact Significant, confidence Medium, signature_severity Critical, tag PCRAT, tag Gh0st, tag RAT, updated_at 2024_07_03;)