alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE UAC-0114/Winter Vivern Screenshot Upload M1"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php"; endswith; http.header; content:"filename|3a 20|S-1-"; fast_pattern; http.content_type; content:"application/x-www-form-urlencoded"; bsize:33; http.request_body; content:"|89 50 4e 47 0d 0a 1a 0a|"; startswith; reference:url,cert.gov.ua/article/3761104; reference:md5,4e2acf4f8a396486ab4268c94a6a245f; reference:url,joesandbox.com/analysis/794564/0/html; classtype:trojan-activity; sid:2044061; 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;)