alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO IncrediMail Install Callback"; flow:established,to_server; http.method; content:"POST"; http.request_body; content:"s=PFNCIHhtbG5zPSJTdGF0aXN0aWNzTlMiPjxBIGlkPSIxIj4"; fast_pattern; startswith; reference:url,www.incredimail.com; classtype:policy-violation; sid:2013499; rev:6; metadata:created_at 2011_08_30, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_13;)