PowerShell Script with Encryption/Decryption Capabilities

event.category:process and host.os.type:windows and
  powershell.file.script_block_text : (
    (
      "Cryptography.AESManaged" or
      "Cryptography.RijndaelManaged" or
      "Cryptography.SHA1Managed" or
      "Cryptography.SHA256Managed" or
      "Cryptography.SHA384Managed" or
      "Cryptography.SHA512Managed" or
      "Cryptography.SymmetricAlgorithm" or
      "PasswordDeriveBytes" or
      "Rfc2898DeriveBytes"
    ) and
    (
      CipherMode and PaddingMode
    ) and
    (
      ".CreateEncryptor" or
      ".CreateDecryptor"
    )
  ) and
  not user.id : "S-1-5-18" and
  not (
    file.name : "Bootstrap.Octopus.FunctionAppenderContext.ps1" and
    powershell.file.script_block_text : ("function Decrypt-Variables" or "github.com/OctopusDeploy")
  )