Extension method to decode an array of bytes

StringExtension.cs

public static class StringExtension
{
	public static string ToReadableMessage(this string stringFromSql)
	{
		var byteList = new List<byte>();

		string hexPart = stringFromSql.Substring(2);
		for (int i = 0; i < hexPart.Length / 2; i++)
		{
			string hexNumber = hexPart.Substring(i * 2, 2);
			byteList.Add((byte)Convert.ToInt32(hexNumber, 16));
		}

		byte[] original = byteList.ToArray();
		return Encoding.UTF8.GetString(original);
	}
}