ET MALWARE [FIREEYE] PULSECHECK Webshell Access Outbound

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE [FIREEYE] PULSECHECK Webshell Access Outbound";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.header_names;
    content:"|0d 0a|X-CMD|0d 0a|"; nocase;
    content:"|0d 0a|X-CNT|0d 0a|"; nocase;
    content:"|0d 0a|X-KEY|0d 0a|"; nocase;
    content:!"|0d 0a|Referer|0d 0a|";
    reference:url,github.com/fireeye/pulsesecure_exploitation_countermeasures;
    reference:url,www.fireeye.com/blog/threat-research/2021/04/suspected-apt-actors-leverage-bypass-techniques-pulse-secure-zero-day.html;
    classtype:trojan-activity;
    sid:2032907; rev:1;
    metadata:attack_target Server, created_at 2021_05_05, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_05_05;
)