alert http1 $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32.Riberow.A (listdir)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/listdir.php?dir="; fast_pattern; http.header_names; content:"|0d 0a|Host|0d 0a|Pragma|0d 0a|Accept|0d 0a 0d 0a|"; startswith; endswith; reference:md5,c55fe941b80b3e5e77be8728642d138e; classtype:trojan-activity; sid:2013668; rev:7; metadata:created_at 2011_09_19, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_14;)