alert tcp $HOME_NET any -> $EXTERNAL_NET [445,139] (msg:"ET MALWARE Locky Ransomware Writing Instructions via SMB"; flow:to_server,established; content:"|FE|SMB|40 00|"; offset:4; depth:6; content:"|05 00|"; distance:6; within:2; content:"_|00|H|00|E|00|L|00|P|00|_|00|i|00|n|00|s|00|t|00|r|00|u|00|c|00|t|00|i|00|o|00|n|00|s|00|.|00|h|00|t|00|m|00|l"; nocase; distance:0; fast_pattern; classtype:trojan-activity; sid:2023148; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2016_09_01, deployment Perimeter, malware_family Ransomware, confidence High, signature_severity Major, tag Ransomware, updated_at 2019_07_26, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;)