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jesselu10

macrumors newbie
Original poster
Jun 21, 2007
9
0
Hi there,

I purchased a Mac mini off eBay a few months ago and just had the time to set it up. It was a good deal - not low enough you can't trust it - but a good deal.

I'm very concerned about security in general. I was 1Password, I make sure my data is secure, I have multiple backups of my data. All that being said - I may be over-thinking this. But just wanted to get another confirmation of my hypothesis.

Anyway - when I got the Mac mini there was a fresh install of SL & a username "new owner" was already set up. Good enough - I used Migration Assistant to transfer over my files & account from my MacBook (did the full transfer option). Then, once I confirmed all was good to go, I deleted the "new user" user on my OS X installation.

I'm curious - since the OS X installation was already set up, is there ANY chance that the original owner of the Mac mini perhaps put a malicious app somewhere that launches at start, under root or something?

I guess I'm most concerned about either a keylogger or screen sharing that I don't know about. However - my hypothesis is that because the ONLY user on this OS X installation now is mine (with a unique password), there's no way for apps or anything to be run without my knowledge, correct? There's no way for the seller to have implanted something malicious deep within the OS X installation that I'm not aware of?

Am I being paranoid or have a valid concern? Should I just go about my business or is there something else I could do to protect myself - like change the firmware password or something?

Thanks so much for all your expertise!!

- Jesse
 
There is always that chance but chances are the guy restored it but walked through the setup that you'd normally see when you turn it on.

If I buy 2nd hand I always do a full erase and install myself. It reduces any of these paranoid concerns that I too would wonder about.
 
Ok - thanks for the hard truth.

I'm thinking my plan of action will be to do a SuperDuper exact copy backup, wipe the Mac mini & re-install SL, then use Migration Assistant to get my files back as they were from the SuperDuper backup.

Worst case scenario - there's malicious app running deep within the system (somehow), there's no way that app could copy itself to my user folder because the user folder is protected by my username/password, correct?

So if I do that procedure, since Migration Assistant would keep the fresh re-install of OS X, I'm 99.9% secure now, correct?

Also - my Time Machine, Backblaze setups should just pick back up where they were left off, correct - because they won't notice anything changed once I start back up my Mac mini after the Migration Assistant?

Thank you,
Jesse
 
Just realized all I had to do was pop in the SL DVD & it would just replace the system, keeping my user folder intact.

Well worth the "trouble"

- Jesse
 
how do you know if your user folder was not compromised by the original other owners system folder?

i would do a complete clean install (erase writing zeros/option) and install
 
how do you know if your user folder was not compromised by the original other owners system folder?

i would do a complete clean install (erase writing zeros/option) and install

The new user folder was created after he got his computer. I don't see any particular need to write zeros... that seems like a bit of overkill to me, but it's certainly not a bad idea.
 
Worst case scenario - there's malicious app running deep within the system (somehow), there's no way that app could copy itself to my user folder because the user folder is protected by my username/password, correct?

Anything running "deep" in a system will have the ability to access the entire filesystem and do as it pleases.
 
Both methods, reinstall and migration from a clone and just reinstalling the OS without erasing would not get rid of potential malicious software.
 
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