alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE PlugX/Korplug CnC Activity"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/script"; bsize:7; http.request_body; content:"v="; startswith; fast_pattern; content:"&id="; distance:0; content:"&uid="; distance:0; content:"&vs="; distance:0; http.header_names; content:!"Referer"; reference:url,www.welivesecurity.com/2021/03/10/exchange-servers-under-siege-10-apt-groups/; reference:md5,26e442aa18fcea38e4c652d346627238; classtype:command-and-control; sid:2032001; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_03_12, deployment Perimeter, malware_family PlugX, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_03_12;)