alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Possible APT Sarhurst/Husar/Hussarini/Hassar CnC Command Response"; flow:established,to_client; http.stat_code; content:"200"; file.data; content:"<CHECK>"; startswith; content:"</CHECK><COMMAND>"; distance:0; fast_pattern; content:"</COMMAND>"; endswith; pcre:"/^<CHECK>(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})<\/CHECK>/"; reference:url,www.fortinet.com/blog/threat-research/hussarini---targeted-cyber-attack-in-the-philippines.html; classtype:targeted-activity; sid:2027708; rev:7; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_07_15, deployment Perimeter, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_13;)