alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE MSIL/Juliens Botnet CnC Activity M1"; flow:established,to_server; http.start; content:"GET /data.php?a="; startswith; fast_pattern; content:"&b="; distance:0; content:"HTTP/1.1|0d 0a|Authorization|3a 20|Basic|20|"; reference:md5,73ed84016746f0b53889d20cbdbb6f07; classtype:command-and-control; sid:2030834; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_09_04, deployment Perimeter, malware_family MSIL_Juliens, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_09_04;)