alert tcp-pkt $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE njRAT v65.0 CnC Checkin"; flow:established,to_server; dsize:<256; content:"|00 00 00|"; offset:1; content:"|00 00 00|"; distance:1; content:"|7c 7c|"; distance:12; pcre:"/^(?:\d{1,3}\.){3}\d{1,3}\|\|/R"; content:"|7c 7c|Microsoft Windows"; content:"|7c 7c ce de 7c 7c ce de 7c 7c ce de 7c 7c 31 7c 7c|65.0"; fast_pattern; endswith; reference:md5,008e86fdb755fb073cf629e2a6b8c783; classtype:trojan-activity; sid:2036933; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2022_06_08, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_06_08;)