alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Alphacrypt/TeslaCrypt Ransomware CnC Beacon Response"; flow:established,to_client; file_data; content:"---!!!INSERTED!!!---"; within:20; reference:md5,ee90ec9935c7b8e1a5dad364d4545851; classtype:command-and-control; sid:2021724; rev:3; metadata:attack_target Client_Endpoint, created_at 2015_08_28, deployment Perimeter, 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;)