Can an applet really slow down my Mac this much, and could I really have a "bot"?

I have a MacBook Pro I got in October 2012. It’s a fast machine. But when I use the Yahoo chess applet (Java), everything slows to a crawl, and the fan goes on full speed and stays on.

Now this applet has barely changed since 1998. It is primitive stuff. How can this POS software possibly cause my new machine to slow down so much?

Next question. I have Comcast as cable. Starting in 2011, they send me an email every few days saying my computer may be infected by a bot. Now there is one other adult in my household with a Windows machine, and it conceivably could have a bot on it.

In any case, before I considered that possibility, I took Comcast’s advice and installed the free Norton Antivirus they offer on my computer. It found nothing.

So, really what are the chances that a bot has infected my computer?

Thanks for your answers!

  1. Launch Activity Monitor and see how much processor time the Applet is consuming. It may be very poorly written, and monopolizing your CPU.

  2. The chance of you having a “bot” is as close to zero as I can imagine. Download Clam AV (avoid Norton, please…) and scan your HD if you are worried.

You could try updating Java or running a different version.

The emails you are getting are most likely some attempt at phishing.
If they’re not; you should call your ISP, maybe they can be more specific as to what the problem is.

As for general anti virus on Windows: the program I’m currently recommending is MSE. It is free, reasonably lightweight and it almost never nags about new versions or updates in a fashion that requires your attention. Most free av-programs want you to upgrade to the paid version and/or install some crapware. MSE might not be the very best in catch-rates but it almost never misbehaves on its own.

I have the latest version of Java. Or at least the latest in the last couple days. :slight_smile:

The emails come directly from Comcast and aren’t phishing. When I talked to them on the phone, they recommended Norton.

I have a Mac, so no Windows (although my sister runs Windows on her Mac for work–sacrilege!).

It doesn’t take a complicated program to use up a lot of computing resources.

As a simple test, you can cause an entire core of your Macbook cpu to be used up with a very simple program called “yes”. Just open up Activity Monitor (to see the effects), open up Terminal, and type “yes” (no quotes) into terminal. You’ll see a row of “y” characters, one per line, printed out, and the Terminal program’s CPU usage will shoot up to around 100%. You can stop it by closing the Terminal window.

The reason “yes” is so resource intensive is that it just does something very simple and repetitive, and does so as fast as the computer’s hardware can manage. More complicated programs generally have a sort of low power or idle state that they go into when they’re not busy, so they don’t use many resources. However, it’s possible to write a program so that, rather than idling, it does what’s called a “busy loop”. Basically, it just constantly churns the processor and checks to see if there’s anything to do yet.

My guess, if Activity Monitor shows that the Chess Applet is really taking up a lot of resources, is that it was written with a busy loop, rather than a proper idle loop.

Yes, I have launched Activity Monitor, and this simple applet is taking up a huge amount of CPU resources. Makes no sense. I used to run this thing on crappy desktops in the late 90s like it was nothing.

Thank you, walrus. The thing is, I’ve used this program on old Windows machines, and it always ran quickly. In fact, I’ve used it on my Mac before, and it was fine.

It seemed like, beyond a certain version of Java, it started running very slow. How is that possible?

Oh, and the applet frequently causes Firefox to crash. :frowning:

Open the Console while it’s running. See if it’s producing a lot of log messages.

5/2/13 12:16:38.653 AM[414]: [QL] Using too much memory (133 MB), hit critical threshold (120 MB), exiting immediately to clean up.

That’s not it…
That’s “Quick Look,” Apple’s preview system (select an item in the Finder, hit the spacebar).

But it’s now 12:21 and nothing since 12:16. Fan is on and machine is running slow.

No, I’m in console.

Try creating a new User, and logging in as that user, and running the applet, and see what happens.
It may be a “preferences” problem.

But, most likely, is a Java bug, and you are just going to have to live with it until it’s fixed.

A lot of old Flash movies made by idio-- ahem “people” who weren’t aware of the proper way of timing animations would just get into an infinite loop of doing nothing but checking the computer’s clock to see if it was time for the next animation frame. It’s possible that old applet is doing something similar… if it’s as old as you say, nobody would have considered the consequences of this on power-saving CPUs (as they didn’t really exist at the time.)

Has it always behaved this way on that laptop, or did it begin after a recent Java update?

It was after a more or less recent Java update. I didn’t seem to have a problem into last year, I think. But I got a new machine last year, so I’m not exactly sure about the timing.