Q: Serious Mac Virus?

1. It is an iMac. What year/model is it?

2. Is your Keyboard USB or BT? Is it an Apple or a different brand?

3. You may want to keep track of how the Magic Mouse behaves. Please look in Console logs for Bluetooth messages.

4. USB messages will also help.

5. You may to take screen shot of the USB and BT from System Information for future reference. BT can be prone to RF interference - Wi-Fi and Bluetooth: Potential sources of wireless interference

6. For the 8pm mystery, it can be either machine initiated or network initiated activity. If you can use Wireshark at around 750pm, and another one at say 805 pm, connections can be analyzed. Terminal netstat -an | grep ESTABLISHED can also show you if anything new is started. If you can write a simple loop script which executes this command at a periodic interval, it can show you connections and how they vary over time.

7. Do you have any NAS devices which may have been configured for backups of devices connected to the network?

8. If you have the ability to install another OS, say Ubuntu or Windows, does the same behavior repeat across multiple OSes? A linux derivative may be better. Virtualization engines will muddy the water further, so a single OS-at-a-time can be used to narrow down issues.

9. I would try and start a 'full' AHT and let it run overnight, if necessary. Such tests are usually run with minimal peripherals being connected, so mouse/keyboard should be the minimum.

10. Do you have another Mac which can be paired with the same peripherals to further narrow down the focus of the diagnostics?

As others have reported a problem that looked like a hacker coming in through their wireless network and manipulating their screen - if you a wireless network change the passwords on it to secure passwords - if you left the default they will just come back in and do the same thing.

Ultimate security on the internet - and your Mac - when you are not using it shut it down - it is hard to hack into a system that is off and the spike stick is shut off.   

diablo9333 wrote:

 

I've never even heard of Wireshark so I probably have never used it.

You don't need to use Wireshark or netstat. Those are tools that are only useful in the hands of an expert. Someone who isn't a networking expert would only be confused by them, assuming they could even run them in the first place.

After using my Magic Mouse it seems to be clear that the problem is with the Trackpad, since with the Magic Mouse it is fine. It still doesn't describe how the issue happened with the cheap mouse I got

If there's a problem with the built-in trackpad, it doesn't matter what external mouse or trackpad you use... the screwed-up input from the internal trackpad is still present, and will still cause the same problems.

Since you have an older MacBook, a strong possibility is the swollen battery that was mentioned in one of the points in Linc's post. Not all older batteries swell when they start to die, but if they do swell, they usually cause problems with the trackpad, which sits right above the battery and has pressure put on it if the battery swells.

I would strongly suggest that you take this machine in to get checked out by Apple. If the battery is swelling, you want to get that taken care of before the pressure breaks something or the battery ruptures and spills its innards all over the insides of your MacBook.

The problem is related to an iMac. The question related to a second Mac was to allow the OP to test the peripherals on a second Mac to isolate peripheral issues. It can also be used to do some Target Disk Mode analysis, if necessary.

Wireshark and netstat can always be learnt.

PS: Ah I see the OP responded as well. Apologies, Thomas on a double post.