alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/ErbiumStealer Panel CnC Checkin"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/api/v1"; startswith; http.user_agent; content:"Erbium-UA-"; startswith; fast_pattern; reference:url,twitter.com/3xp0rtblog/status/1556256431904546816; classtype:command-and-control; sid:2038480; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_08_09, deployment Perimeter, malware_family Erbium, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_08_09;)