alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET ADWARE_PUP PUP Optimizer Pro Adware Download"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/OptimizerPro.exe"; nocase; endswith; fast_pattern; http.header_names; content:!"Referer"; reference:url,malwr.com/analysis/NjdkMTczMDQ0MDQ0NGNmZWE0OTgzYTY2YzU5OGY2YmI/; classtype:pup-activity; sid:2018743; rev:6; metadata:created_at 2014_07_21, signature_severity Minor, updated_at 2020_09_17;)