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;)