alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE SYS01 Information Stealer - CnC Checkin"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"?a=http&dev=1&v="; fast_pattern; content:"machine_id="; content:"from=SYS01"; content:"tag="; content:"uname="; content:"mt="; content:"f="; reference:url,blog.morphisec.com/sys01stealer-facebook-info-stealer; classtype:trojan-activity; sid:2044505; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_03_07, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_03_07;)