alert http1 $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Cryptowall 2.0 DL URI Struct Oct 2 2014"; flow:established,to_server; http.request_line; content:"GET /blog/"; fast_pattern; startswith; pcre:"/^[a-z0-9]+\x20HTTP/R"; http.user_agent; pcre:"/(?:MSIE|rv\x3a11\.0)/"; http.header_names; bsize:37; content:"|0d 0a|User-Agent|0d 0a|Host|0d 0a|Cache-Control|0d 0a 0d 0a|"; reference:url,malware-traffic-analysis.net/2014/10/01/index.html; classtype:trojan-activity; sid:2019341; rev:7; metadata:created_at 2014_10_02, performance_impact Moderate, signature_severity Major, updated_at 2024_04_14;)