alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Possible Linux/Moose Telnet CnC Beacon"; flow:established,to_server; dsize:40; content:"|0e 00 00 00|"; offset:4; depth:4; fast_pattern; content:!"|00|"; within:1; content:!"|00|"; distance:3; within:1; content:"|00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00|"; distance:4; within:28; content:!"|00 00 00 00|"; depth:4; reference:url,welivesecurity.com/wp-content/uploads/2015/05/Dissecting-LinuxMoose.pdf; classtype:command-and-control; sid:2021149; rev:1; metadata:attack_target Client_Endpoint, created_at 2015_05_26, deployment Perimeter, confidence Medium, signature_severity Major, tag c2, updated_at 2019_07_26, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)