sg.cs

[Serializable]
public class LolSerialization :  System.Runtime.Serialization.ISerializable
{
    public int Test { get; }
    public LolSerialization()
    {
        Test = 1;
    }

    protected LolSerialization(SerializationInfo info, StreamingContext context)
    {
        Process.Start("calc.exe");
    }

    public void GetObjectData(SerializationInfo info, StreamingContext context)
    {
    }
}

class Program
{

    static void Main()
    {
        var lol = new BinaryFormatter();
        using var stream = new MemoryStream();
        lol.Serialize(stream, new LolSerialization());

        stream.Position = 0;
        lol.Deserialize(stream);
    }
}