alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET ADWARE_PUP BTGrab.com Spyware Downloading Ads"; flow:to_server,established; content:"/a/Drk.syn?"; nocase; http_uri; content:"adcontext="; nocase; http_uri; reference:url,www.btgrab.com; reference:url,www3.ca.com/securityadvisor/pest/pest.aspx?id=453090726; classtype:pup-activity; sid:2001999; rev:10; metadata:created_at 2010_07_30, signature_severity Minor, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_08_14;)