alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Storm/Waledac 3.0 Checkin 2"; flow:established,to_server; content:"|01 02 01 01|"; fast_pattern; http.method; content:"GET"; http.host; pcre:"/^(?:\d{1,3}\.){3}\d{1,3}$/"; http.request_line; content:".htm HTTP/1.1"; http.content_len; byte_test:0,<,100,0,string,dec; http.header_names; content:"Host|0d 0a|"; content:"Content-Length|0d 0a|"; classtype:command-and-control; sid:2012139; rev:10; metadata:created_at 2011_01_05, signature_severity Major, updated_at 2020_10_28;)