alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE ChromeLoader CnC Checkin M1"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/x?u="; fast_pattern; startswith; pcre:"/^\d{19}/UR"; content:"is="; pcre:"/^\d{10}/UR"; content:"lv="; content:"rv="; reference:md5,ad13ce579df176b2c7ab440dd8d2252a; classtype:trojan-activity; sid:2039746; rev:1; metadata:created_at 2022_11_07, deployment SSLDecrypt, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_11_07;)