public interface IUserContext {
    User CurrentUser { get; }
}

container.Register<IUserContext>(() => {
    User user = null;
    try {
         user = HttpContext.Current?.Session[USER_CONTEXT] as IUser;
    }
    catch { }

    return new UserContext(user);
});

public static Func<User> UserContext { get; set; }

using (container.BeginLifetimeScope()) {
    .....
    var user = GetUserContext(message);
    UserContextInitializer.UserContext = () => new UserContext(user);
    .....
}

container.Register<IUserContext>(() => UserContextInitializer.UserContext);