Preparing a used macbook pro for personal use

Hi, all.


I'm reaching out to the Apple Support Community to determine: 1) if my chosen course of action is a sufficient one to address my concerns; and 2) if there is anything else I could do to further address my concerns.


I recently purchased a used mid-2015 Macbook Pro 15" (2.2 Ghz processor; 256 GB SSD) off of craigslist. Prior to purchase, it looks like the Macbook Pro was reset to factory settings by the previous owner.


My two primary concerns center on residual (i.e., unintentionally installed) malicious code from the previous user and intentional malicious code that may have been put there by the previous owner. And to just make sure we're on the same page, by using the phrase "malicious code," I'm collectively referring to malware, viruses, etc.


I believe the previous factory reset on the Macbook should have taken care of these two primary concerns, but I'd feel more comfortable doing things myself. As a result, I plan on performing an internet recovery on the Macbook to erase the SSD and the current recovery partition on that SSD, in addition to performing a clean install of the Mac OS that was originally installed on the Macbook. I decided to perform an internet recovery instead of a local recovery (using a bootable USB drive) because, from what I understand, the local recovery won't actually erase the current recovery partition on the 256 SSD.


Do you folks think these two steps are sufficient to rid the Macbook of any potential malicious code that was unintentionally/intentionally installed? Additionally, is there anything else I can do prior to transferring over my data onto the new-to-me Macbook?


Thanks in advance, everyone.

MacBook Pro with Retina display, macOS Sierra (10.12)

Posted on Feb 21, 2017 5:28 PM

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9 replies

Feb 21, 2017 5:35 PM in response to SlrGuy

I've purchased a used Macbook Pro for my niece about a year ago - even though the previous owner reset to factory settings - I always have a usb installer handy and do a clean install - erase the whole drive then reinstall Mac OS.


Not being paranoid, I just prefer to do a clean install myself.


So I fully understand your thoughts and concern. I just prefer via USB since it's faster than internet recovery.

Feb 21, 2017 5:49 PM in response to Oceanis34

Thanks for the response.


I totally understand the speed advantage of local recovery (via bootable USB) compared to internet recovery. However, as mentioned in my original post, I don't believe a local recovery will erase/recreate the current recovery partition on the SSD.


Granted, I'm not even sure if malicious code could be installed, either by the previous owner or by the malicious code itself, in the recovery partition of the SSD. Furthermore, an assumption underlying my choice of recovery is that internet recovery erases/recreates the recovery partition of the SSD while a local recovery does not. I could be wrong there.

Feb 21, 2017 6:03 PM in response to Oceanis34

Ah!


I guess this would be the difference between holding "command R" and "option" when first turning on the Macbook, correct? "Command R" takes you to the recovery partition, while "option" gives you the option of directly going to the bootable USB?


If that's the case, then I guess I missed the distinction when looking at various online guides I found.

Feb 21, 2017 6:41 PM in response to Oceanis34

Thanks for the link and the clarification. It's definitely appreciated.


Good to know that the entirety of the SSD is erased (including the recovery partition) is erased via the bootable USB installer (or internet recovery). As a result, any malicious code that was there will be gone (or at the very least, not functional anymore).


Is there any other location where malicious code could be hiding? I suppose it really doesn't matter, since those other places wouldn't really be accessible by me (or by the person that had hands on the Macbook before me)?

Feb 21, 2017 6:55 PM in response to SlrGuy

If we were talking about PC then I would tell you to change the hard drive when it comes to malicious codes - i remember back in the days when I ended up with 2 dead motherboards because of those codes that corrupts your BIOS. But that was 10 - 15 years ago.


Since we're talking mac here - the chances are slim to none.


I have purchased a few used MacBooks in the last 5 years for friends and relatives and have never had any issues.


I think you'll be fine once you erase your drive and do a clean install.


Good luck

Feb 21, 2017 7:09 PM in response to Oceanis34

This is my first used computer purchase, so I guess I'm overly paranoid about things. Especially since I think I got an unbelievable deal on the mid-2015 15" Macbook Pro ($1000!) and the whole "something that's too good to be true probably is" thing.


At minimum, I looked up the serial # and confirmed that the Macbook was purchased legitimately.


Thanks again for the advice.

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Preparing a used macbook pro for personal use

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