alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET POLICY Observed MSI Download"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".msi"; endswith; http.user_agent; content:"Windows Installer"; bsize:17; fast_pattern; classtype:policy-violation; sid:2048100; rev:5; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2018_08_22, deployment Perimeter, performance_impact Moderate, confidence High, signature_severity Informational, updated_at 2023_09_18, reviewed_at 2024_02_16, former_sid 2832259;)