alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET ADWARE_PUP AdWare.Win32.BetterSurf.b SSL Cert"; flow:established,to_client; tls.cert_subject; content:"CN=*.tr553.com"; threshold:type limit, track by_src, count 2, seconds 60; reference:md5,54c9288cbbf29062d6d873cba844645a; classtype:pup-activity; sid:2020712; rev:6; metadata:attack_target Client_Endpoint, created_at 2015_03_19, deployment Perimeter, confidence High, signature_severity Major, tag SSL_Malicious_Cert, updated_at 2024_04_24;)