alert tcp any any -> any $SSH_PORTS (msg:"ET MALWARE Linux/Kimodin SSH backdoor activity"; flow:established,to_server; content:"SSH-2.0-"; depth:8; isdataat:22,relative; pcre:"/^[0-9a-f]{22,46}/R"; reference:url,www.welivesecurity.com/wp-content/uploads/2014/03/operation_windigo.pdf; reference:url,github.com/eset/malware-ioc; classtype:trojan-activity; sid:2018264; rev:8; metadata:created_at 2014_03_13, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)