Mac 10.6.8 on macbook pro
I just downloaded mackeeper from what I thought was a reliable site. Unfortunately, I don't remember exactly what site. I thought I remembered mackeeper as one of the recommended programs from previous reading but apparently I was wrong. I haven't installed it since I intended to read up on it before installing and trying to use it. I googled mackeeper to start reading up on the program and there were two links to mackeeper.com listed. When I followed either link I got a warning that this was an unreliable page - once by WOT and I think Noscript gave me the other warning - so I exited those pages.
Technically, MacKeeper appears to nominally be "legitimate" software, although many don't agree. The issue is that people typically claim it does not do what it says and can actually slow down a Mac. And from what I have read, it can be a real pain to uninstall. You can read about at least one person's opinion here:http://www.imore.com/avoid-mackeeper
I have never used it myself, so I cannot really comment on how good or bad it may be. Instead, I can only offer what I read from other people.
So I took myself to bleepingcomputer and searched for mackeeper in this forum and in one topic - mostly over my head - it said mackeeper was fake software. So can I expect trouble just from downloading or will sending it to the trash bin be enough?
If you did not install it (installing should have required you to enter your Admin account password), then you should be able to just delete the install file and be fine. This assumes it is the "official" Mackeeper app installer. If it is something else, then there is a slight chance it might be more involved, but I kind of doubt it.
One thing I really miss from windows is the ability to skip the trash can and use ctrl+del to do a final delete on a file. Using Mac's version of command prompt to delete a file is very cumbersome, plus I've forgotten how.
I believe starting with El Capitan (aka 10.11.x) that Apple added the ability to instantly delete a file. This is done be holding down the Option key, which should then turn the normal "Move to Trash" to "Delete Immediately". I cannot confirm this as I am currently still running 10.10.x at the moment (soon to update to at least 10.11, if not 10.12). This article describes this new ability in El Capitan:http://www.techradar.com/how-to/computing/apple/os-x-el-capitan-how-to-delete-files-faster-on-mac-1306035
As you can see I haven't updated either my mac os or firefox in a while. I'm ill with absolutely no energy, but I'm trying to get things up to date again at this point. I switched from windows to mac 6 years ago, but I've never really gotten comfortable w/ mac. Fortunately, the mac is so much more reliable than windows. Mostly it just works. If I'd still had a windows machine and given it as little attention as I have my mac the last few years I'd have a dead computer.
FWIW, you should update to at least 10.10.x if you can. That should allow you to keep getting security updates (at least until 10.13 is released presumably next year). Plus, there are lots of security updates compared to 10.6.x. It will depend on the model of your MacBook Pro as well as what Apple will still let you get. Generally, only the newest version of the macOS (i.e. Sierra aka 10.12.x) is readily available through the Mac App Store. I believe, however, that you can call Apple to get older versions...but I could be wrong.
Edited by smax013, 08 November 2016 - 01:45 PM.