Disappearing desktop, automatic copying of photos, etc.

[ogonczyk]

Hello,

A few days ago our MacBook was left on (but without any programs running) for about an hour or two. When my wife came back, she heard from it a voice speaking in Chinese and there was some activity going on, something about "download in progress". Afterwards, the desktop items completely disappeared and the entire contents of the iPhoto files were invisibly copied onto the desktop. However, these duplicates cannot be accessed; when we click on them, the message says that they are being in use by the system.

I know that this is not only weird but also very imprecise; I can't describe it any better, though, since I have only heard about it from my wife. Now the laptop is very slow, the desktop icons reappear after we click on the space where they should be but then they disappear again after the shutdown.
Strangely enough, the memory does not seem to be affected by the supposed duplication of picture files from iPhoto.

It all looks like a virus or a malware but I have run several different scans and they showed nothing. Any advice will be greatly appreciated.

 

[simsaladimbamba]

First: It is not a virus.

The only anti-virus you need to protect your Mac is education and common sense.

Mac Virus/Malware Info​

Second: Take a look at DiskInventory X, OmniDiskSweeper, JDisk Report or GrandPerspective to see where the HDD space went to.
Btw, "memory" is not the same as "hard drive capacity":
What is Computer Memory? RAM vs Hard Drive
RAM vs. Hard Disk

Third: What Mac and Mac OS X version does your wife use?

Identify your Mac and Mac OS X version, visualised in a more elaborate image​

Fourth: Can you provide a screenshot of the Desktop?

Fifth: Does anyone else have access to that Mac?

 

[ogonczyk]

Thank you for your reply. Re first: Yes, it looks more like hijacking. Re second: I don't know if any HDD space has disappeared - how can I find out its size before the incident? Re third: MacBook, Mac OS X, version 10.5.8 (I am not using this laptop now, I just copied the info from "About This Mac"). Re fourth: since I am not using the MacBook in question, I don't know how to get a screenshot of the desktop to you; anyway, there is absolutely nothing on it. Re fifth: Yes, three people altogether. I was the last one to use it, to download mp3 files from www.librivox.org (I had done this hundreds of times before with no ill effects whatsoever.)