alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Link Implant CnC Activity (POST)"; flow:established,to_server; http.request_line; content:"POST /static/"; http.cookie; content:"banner=banner"; fast_pattern; bsize:13; http.header; content:"x-request-id|3a 20|"; startswith; http.header_names; content:!"Referer"; reference:url,github.com/postrequest/link; classtype:command-and-control; sid:2037930; rev:1; metadata:attack_target Client_Endpoint, created_at 2022_08_04, deployment Perimeter, deployment SSLDecrypt, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_08_04;)