alert http1 $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Mustang Panda APT Related Activity (GET)"; flow:established,to_server; flowbits:set,ET.mustangpanda.numbymane; urilen:1; http.method; content:"GET"; http.header_names; content:"|0d 0a|User-Agent|0d 0a|Sec-Dest|0d 0a|Sec-Site|0d 0a|Host|0d 0a 0d 0a|"; endswith; http.header; content:"|0d 0a|Sec-Dest|3a 20|"; fast_pattern; pcre:"/^[0-9A-Za-z]{8}\r\n/R"; content:"Sec-Site|3a 20|"; distance:0; pcre:"/^[0-9A-F]{20}\r\n/R"; reference:url,twitter.com/StopMalvertisin/status/1635620870214352901; reference:url,twitter.com/t3ft3lb/status/1635597523434762240; reference:md5,15c74f8c597d2937abae779ee5ef95d7; reference:md5,821ec39800471963a4ccef10b587b8d6; classtype:trojan-activity; sid:2044639; rev:2; metadata:attack_target Client_Endpoint, created_at 2023_03_16, deployment Perimeter, deployment SSLDecrypt, malware_family MustangPanda, malware_family NUMBYMANE, performance_impact Low, confidence High, signature_severity Major, tag TA416, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_03;)