alert http $HOME_NET any -> $EXTERNAL_NET [!80,!443] (msg:"ET MALWARE Possible TA410 APT FlowCloud Dependency Download"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".DAT"; endswith; pcre:"/\/[A-Z0-9]{4,8}\/[A-Z0-9]{8}\.DAT$/"; http.header_names; content:"|0d 0a|Host|0d 0a|Cache-Control|0d 0a 0d 0a|"; depth:25; http.host.raw; content:"|3a|"; classtype:trojan-activity; sid:2036388; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_10_12, deployment Perimeter, malware_family TA410, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_12;)