alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Colibri Loader Activity M3"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php?type=update&uid="; fast_pattern; pcre:"/^[0-9A-F]{16,32}$/R"; http.content_type; content:"application/x-www-form-urlencoded"; bsize:33; http.user_agent; content:!"Mozilla"; content:!"Safari"; content:!"Opera"; pcre:"/^[A-Za-z0-9]{16,32}$/"; http.header_names; content:"|0d 0a|Content-Type|0d 0a|User-Agent|0d 0a|Host|0d 0a|"; startswith; content:!"Referer"; reference:md5,a56fea310f3cf5e724ee4a9990047b78; reference:url,twitter.com/3xp0rtblog/status/1489245446883069954; classtype:command-and-control; sid:2035108; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_02_05, deployment Perimeter, malware_family Colibri, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_02_05;)