alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Zeprox.B Checkin"; flow:to_server,established; http.method; content:"GET"; http.uri; content:".php?a=n|60|e|3e|"; fast_pattern; http.header; content:"Proxy-Connection|3a|"; http.header_names; content:!"Referer|0d 0a|"; http.content_len; byte_test:0,=,0,0,string,dec; reference:md5,bc27f28e5fe47b78202fd3108d39aac1; reference:md5,38c89cca7806fde08bba82b3cb533e5a; reference:url,www.microsoft.com/security/portal/threat/encyclopedia/entry.aspx?Name=Backdoor%3AWin32/Zeprox.B; classtype:command-and-control; sid:2020203; rev:8; metadata:created_at 2015_01_16, malware_family Win32_Zeprox_B, signature_severity Major, updated_at 2020_12_22;)