Hi!

My dad has a 2007 iMac. He bought McAfee, fearing viruses, for he surfs the internet a lot. Is there a real virus threat? Doesn't it really slow down the Mac? Do you use McAfee? Has the situation really changed on the Mac?

McAfee found some threats instantly, about 30, put some mails into quarantine an deleted some files etc. Seemed to work on something.

Is it necessary? Won't the Mac be too slow in the end? They email and surf rather much, my parents.

Greetings,
PeterParker

[Mike Wuerthele]

I'm of a mixed mind about this, and I've spoken a little about it in another thread. While there aren't loads of Mac-specific malware packages or virii, there are a lot of Flash and Java-based ones. At this particular moment, it depends a lot on how much your parents know about the OS.

When the OS throws up a user authentication box for an install, are they aware of what it's for, or do they just blindly enter their password? Modern Macs, including the 2007 iMac, aren't going to be impacted much, if at all, performance-wise by legitimate anti-malware packages, assuming that they have enough RAM to reduce page-outs.

[andi*pandi]

My work requires it, but running it at home I find sometimes the scanning can take forever and slow down the mac. I shut off Sophos scanning for that reason, but left the internet filter on, and it was savvy enough to alert me when one of my clicks brought me to an unsavory dark alley.

It all depends on how savvy they are and what they click, and where they get their apps.

[Mike Wuerthele]

Yeah, let me clarify my previous statement. Active file scanning is a bit of an I/O hog, and dramatically slows hard drive access times when you're trying to get actual crap done. Things like what andi*pandi mentioned about internet dark alleys? Yeah, that's very resource-light.

[OreoCookie]

You should install an ad blocker such as Ghostery and de-install Flash. That takes care of a crapload of malware, and keeps your dad from inadvertently downloading stuff. That also speeds up web browsing, so it's really a win-win.

[ghporter]

A long time ago, McAfee was a great asset, at least in the Windows world. But several years ago they went in some odd direction and their product became less useful, even in the Windows world. I have never seen a good example of McAfee doing anything useful for a Mac.

Norton, on the other hand, was (at least relatively recently) still a solid protection package. My graduate school provided the "managed" version for school machines, and the "unmanaged" version for student machines, and as recently as 2012 it was still doing its job well. But examining logs around that time, I became aware of this: Norton never found a single thing that was "questionable" on my Macs.

My bottom line: for Windows, go with ClamAV (the free version) and keep it up to date; for Macs, I don't know of a good reason to use a "live" antivirus product (like a Windows machine needs) on a Mac, though ad blockers and browser extensions that let you control pop-ups, Flash and other annoyances are a solid choice. Chrome for Mac automatically installs AdBlock Plus, and the Chrome extension Flashcontrol, do a lot to keep my browsing interruption free.

[Mike Wuerthele]

This isn't the place for the conversation as a whole, but places that don't abuse you advertising-wise, you shouldn't block. If you do, for personal reasons, see if there's something else you can do to benefit sites you frequent. Don't rely on other people to pay their bills.

Quality content costs money.

[OreoCookie]

Originally Posted by Mike Wuerthele 

This isn't the place for the conversation as a whole, but places that don't abuse you advertising-wise, you shouldn't block. If you do, for personal reasons, see if there's something else you can do to benefit sites you frequent. Don't rely on other people to pay their bills.

I've included ad blockers for a very specific reason: there are certain types of websites which make up a sizable share of the web traffic, that include a lot of malicious advertising (e. g. via downloads of “special” video codecs) and ask people to download all sorts of software. I've had that happen to a family member. One of the best ways to prevent them from getting bitten by these types of bugs are ad trackers. (I should have explained my rationale in my first post, though.)

[Curiosity]

If you want an ad blocker, why not use something like Adblock Plus or Safari Adblocker with Adblock Plus subscriptions? Ghostery is supposed to stop tracking, but not ads specifically.
When I was using Windows, I tried McAfee Antivirus, but it really slowed down the boot process. When I got a different antivirus, things were a lot faster.
With Mac OS, I am using Clam antivirus, and am pleased with it. I have it watching the download directory and the Applications directories, which is where viruses are most likely to show up.

[driven]

My company makes it a requirement for me to have it on my (i7 Quad) MBP. I personally don't think it's necessary for most users with common-sense (I don't have it on my personal iMac).

However: Unlike years past, I find it doesn't really slow down my MBP for day to day use. Perhaps it would for heavy disk and DB I/O, but I haven't noticed any issues. (I do a lot of development and often run two to four VMware machines at a time.)

So, my assessment: No discernible performance hit, and "it can't hurt" virus protection.

[P]

SSDs tend to reduce the load from antivirus programs. The slowdown is mostly that they eat all the available disk IO, and when the available disk IO goes up, the antivirus programs get done quicker and anyway bottleneck on things other than disk IO.