Help. iMac 24in won't boot after Facebook link: Virus?

[Racineur]

Hi, I'm writing this post on behalf of my sister. Her 24 inch iMac OS X El Capitan won't boot after she clicked a link in a message sent to her on Facebook by a friend she knows very well. Here are the symptoms. After clicking the link, all of her Facebook messages disappeared but her Mac worked as well as any other day. Then this morning it just wouldn't boot all the way to the desktop. When started, the white progression almost immediately turns black and the background is a grayish white. I could have her boot in recovery mode and use Disk Utility and do the SOS but that's about it. We also tried to restore from a backup. All the backups are on an external HD but DU wouldn't let us to navigate to the disk. I'm afraid the backups are made with the native Western Digital app. That's where we are now. Any hints? The last option would be to erase and reinstall El Capitan...

 

[chscag]

Well, it's not a virus because there are none in the wild that can infect a Mac. Malware yes, viruses no.

It sounds like her hard drive may have gone south. Probably coincidental after she clicked on the Facebook link. A 24" iMac is an old machine and if it has the original hard drive in it, that could be the problem. When you had her boot to recovery and perform First Aid on the hard drive, what were the results?

Also, you could have her try to boot to safe mode to see if the machine will respond. Hold down the shift key as soon as you hear the Bong! sound and keep holding it until the Apple appears.

 

[Trebuin]

Technically after the redefinition of all the various things that could infect computers...there are no computer viruses in existence...they've all been redefined as worms, cryptoware, malware, etc. so Apple users can claim they can't be infected by computer viruses...under that, neither can Windows because of the lack of any hostile program falling under what's left of the "computer virus" category. But taking the original definition of a computer virus, it could very well be something that caused it, but where to go from here is besides the point.

I would run Apple Diagnostics to make sure everything is working on the hardware side (though that's a very basic test & misses a lot). If that runs fine, check to see if you can access the disk & if so, copy all the user folder data to another backup. After than, do a clean install to the operating system you want, either the originally installed or the current version, or original, then upgrade to the version you want. After that, copy your files back & slowly reinstall.

You could run a virus scan, but Apple should have a way to prevent most hostile programs from running & the ones that can do damage usually ask for administrator login to modify key elements of the operating system.

 

[Sid The Kid]

What about running Malwarebytes for Mac scan?

 

[Racineur]

Hi and thanks s much fro your answers. We did run Apple Diagnostics and all was fine. We also did a SOS with Disk Utility. After three tries, the iMac finally booted and we grabbed Malwarebytes which found some malware actually. Since then the old beast runs great, that is being an old timer. So grateful to you all.
Thanks again from both of us, sister and brother

 

[Sid The Kid]

Hi and thanks s much fro your answers. We did run Apple Diagnostics and all was fine. We also did a SOS with Disk Utility. After three tries, the iMac finally booted and we grabbed Malwarebytes which found some malware actually. Since then the old beast runs great, that is being an old timer. So grateful to you all.
Thanks again from both of us, sister and brother

I also suggest you to keep Malwarebytes in the iMac because it's just too good to be removed. You're welcome.