alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Colibri Loader Activity M2"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php?type=ping&uid="; fast_pattern; pcre:"/^[0-9A-F]{16,32}$/R"; http.user_agent; content:!"Mozilla"; content:!"Safari"; content:!"Opera"; pcre:"/^[A-Za-z0-9]{16,32}$/"; http.content_len; byte_test:0,=,0,0,string,dec; http.header_names; content:"|0d 0a|User-Agent|0d 0a|Host|0d 0a|Content-Length|0d 0a|"; startswith; content:!"Referer"; reference:md5,a56fea310f3cf5e724ee4a9990047b78; reference:url,twitter.com/3xp0rtblog/status/1489245446883069954; classtype:command-and-control; sid:2035107; rev:1; metadata:created_at 2022_02_05, malware_family Win32_Colibri, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_02_05;)