alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET INFO Powershell Base64 Decode Command Inbound"; flow:established,from_server; file.data; content:"[System.Text.Encoding]"; nocase; content:"[System.Convert]::FromBase64String"; nocase; fast_pattern; within:100; classtype:misc-activity; sid:2036760; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_06_02, deployment Perimeter, confidence High, signature_severity Minor, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_06_02, reviewed_at 2024_05_07;)