alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Possible Darkhotel Higasia Downloader Connectivity Check"; flow:established,to_server; urilen:15; http.method; content:"HEAD"; http.uri; content:"/view/index.php"; http.user_agent; content:"Mozilla/4.0 (compatible|3b 20|MSIE 8.0|3b 20 20|Windows NT 6.1)"; fast_pattern; reference:md5,0e1ed07bae97d8b1cc4dcfe3d56ea3ee; reference:url,github.com/blackorbird/APT_REPORT/blob/master/Darkhotel/higaisa/higaisa_apt_report.pdf; classtype:command-and-control; sid:2028935; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_11_04, deployment Perimeter, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_21;)