alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET ADWARE_PUP LNKR CnC Activity M2"; flow:established,to_server; threshold:type limit, track by_dst, count 1, seconds 120; http.method; content:"GET"; http.uri; content:"/optout/get?jsonp="; depth:18; fast_pattern; content:"&key="; distance:16; within:23; content:"&t="; distance:18; within:21; reference:url,securitytrails.com/blog/lnkr-malicious-browser-extension; classtype:pup-activity; sid:2027420; rev:4; metadata:affected_product Web_Browsers, affected_product Web_Browser_Plugins, attack_target Client_Endpoint, created_at 2019_06_03, deployment Perimeter, performance_impact Low, confidence High, signature_severity Minor, updated_at 2020_08_31;)