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;
)