alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Suspected PlugX Checkin Activity (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; pcre:"/^\/[a-zA-z]{14}\//U"; content:"/update.php"; endswith; fast_pattern; http.header_names; content:"|0d 0a|Host|0d 0a|Connection|0d 0a 0d 0a|"; bsize:22; reference:md5,ab96e541284afe6ffc3fcf4d05bc971e; reference:url,twitter.com/vupt_bka/status/1497147010927194112; classtype:trojan-activity; sid:2035292; rev:2; metadata:attack_target Client_Endpoint, created_at 2022_02_25, deployment Perimeter, malware_family PlugX, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_03_22;)