alert tcp-pkt $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE ELF/RapperBot CnC Checkin M1"; flow:established,to_server; content:"|d4 1c 74 44 70 95 28 ff f0 98 ae 4e 6f 92 ba d5 0f cd 56 29 c5 12 53 a1 fe 46 53 c7 0b b5 18 27|"; startswith; fast_pattern; reference:url,fortinet.com/blog/threat-research/rapperbot-malware-discovery; classtype:command-and-control; sid:2037961; rev:1; metadata:affected_product Linux, attack_target Client_Endpoint, created_at 2022_08_08, deployment Perimeter, malware_family ELF_RapperBot, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_08_08;)