Rule History

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Ursnif Checkin"; flow:established,to_server; content:"no-cache|0d 0a 0d 0a 0d 0a|"; endswith; http.method; content:"POST"; http.uri; pcre:"/^(?:\/\w{3,12}){2,4}\?[a-z]{3,12}=(?:[A-Za-z0-9+/\x20]{4})*(?:[A-Za-z0-9+/\x20]{2}==|[A-Za-z0-9+/\x20]{3}=|[A-Za-z0-9+/\x20]{4})$/"; http.header; content:"|0d 0a|Content-Length|3a 20|2|0d 0a|Connection|3a 20|"; fast_pattern; http.header_names; content:!"Referer|0d 0a|"; reference:md5,dfeaae9cb1bc24ac467411955e48483b; reference:url,csis.dk/en/csis/news/4472/; classtype:command-and-control; sid:2019377; rev:8; metadata:created_at 2014_10_09, malware_family Win32_Ursnif, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_11_05;)