alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE UAC-0114/Winter Vivern CnC Activity"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/usersfolders/S-1-5-21-"; fast_pattern; reference:url,cert.gov.ua/article/3761104; reference:md5,4e2acf4f8a396486ab4268c94a6a245f; reference:url,joesandbox.com/analysis/794564/0/html; classtype:command-and-control; sid:2044064; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_02_02, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_02_02; target:src_ip;)