alert http $HOME_NET any -> $EXTERNAL_NET $HTTP_PORTS (msg:"ET DELETED C4tdownload.com Access, Likely Spyware"; flow:to_server,established; content:"Host|3a|"; nocase; content:".c4tdownload.com"; within:26; nocase; reference:url,sarc.com/avcenter/venc/data/adware.clickdloader.b.html; classtype:trojan-activity; sid:2001531; rev:14; metadata:created_at 2010_07_30, signature_severity Unknown, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)