alert ftp $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE REvil Exfil SFTP Certificate Inbound"; flow:to_client,established; content:"Kanzas City"; nocase; fast_pattern; content:"System IT Inc"; content:"|55 04 03|"; content:"|06|server"; distance:1; within:7; reference:url,thedfirreport.com/2021/03/29/sodinokibi-aka-revil-ransomware/; classtype:targeted-activity; sid:2033205; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_06_30, deployment Perimeter, malware_family Ransomware, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_06_30, reviewed_at 2024_05_06;)