alert tcp $EXTERNAL_NET ![443,80] -> $HOME_NET any (msg:"ET MALWARE ELF/MooBot Mirai DDoS Variant Server Keep Alive"; flow:established,to_client; dsize:4; content:"|13 11 18 19|"; threshold:type threshold, count 4, seconds 40, track by_src; reference:md5,b3be367b4868d39d6978d27f4d4dfaaf; reference:url,www.fortinet.com/blog/threat-research/mirai-based-botnet-moobot-targets-hikvision-vulnerability; reference:url,blog.netlab.360.com/ddos-botnet-moobot-en/; classtype:command-and-control; sid:2034639; rev:2; metadata:affected_product Linux, attack_target Client_Endpoint, created_at 2021_12_09, deployment Perimeter, malware_family ELF_MooBot, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_12_09;)