alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET ADWARE_PUP OSX/Adware.Pirrit Web Injects"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/mu?id="; fast_pattern; content:"&d="; content:"&cl="; pcre:"/\/mu\?id=[A-F0-9]{8}-[A-F0-9]{4}-[A-F0-9]{4}-[A-F0-9]{4}-[A-F0-9]{12}&d=[A-Za-z]+&cl=\d+$/i"; reference:url,go.cybereason.com/rs/996-YZT-709/images/Cybereason-Lab-Analysis-OSX-Pirrit-4-6-16.pdf; reference:md5,85846678ad4dbff608f2e51bb0589a16; classtype:pup-activity; sid:2022719; rev:4; metadata:created_at 2016_04_08, confidence High, signature_severity Minor, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_31;)