Blog Archives

protect your mac from malware, viruses and other threats

Nessus Vulnerability Software

If you’re new to Mac, you’re probably thinking that it’s a no-brainer that you need some kind of anti-virus app. Once you start looking around the web for reviews, it’s inevitable that you’re going to come across the Great Mac AntiVirus Debate: in the one corner, those who say Mac users who forego antivirus protection are arrogant and just setting themselves up for a fall, and in the other those who’ve used Macs for umpteen years, never had or heard of any real threat, and consequently say AV software is a waste of time.

You can read round this debate for years and never come to a satisfying conclusion, largely because its as much about what you ‘ought’ to do as it is about what is the case. Just because you’ve never had any viruses, doesn’t mean you won’t get one tomorrow. And yet, there are NO viruses in the wild known to affect macs, and so when one does arrive, it will be unknown to your AV scanner. Hence, an AV Scanner is just a waste of system resources (and possibly money, if you paid for it). Yikes! What do I do!!

What you do is sidestep the whole debate and stop thinking only about virus scanners, which after all deal with only a small subset of all the possible attack vectors in the internet age, and start thinking in terms of vulnerability scanners. Unlike a simple virus scanner, a vulnerability scanner examines your system not only for malware but also for any vulnerabilities in commercial software, plug ins, your system setup (including network and other sharing settings) and other installed items. The scanner will not only explain the threat and its severity but also tell you what, if anything, you need to do, recommend patches and guide you to links for more info where available.

You can use something like Nessus for free if you are a home user, which will give you a far better insight into the possible attacks someone could implement on your system (and it will check your system against almost all of the major virus scanner databases like Symantec, etc).

Even better, a vulnerability scanner like Nessus won’t just examine your machine, it’ll look at everything else (and all the installed apps) of anything on your home network including phones (any platform), other computer systems (any OS), and even your router.

creating secure folders and files

With FileVault 2 having a number of drawbacks, a common question I’m seeing is how best to secure data on Lion and Mountain Lion without using FV2.

There’s a number of tricks on offer, from making transparent folders, excluding folders from Spotlight, or using Terminal to make them invisible or hidden.

However, all of these methods suffer from one inevitable drawback: anyone who knows their way around Terminal can open, read, copy or delete your folders as if you had never employed any of the above tricks at all. Well, not many people know their way around Terminal you say? But everyone knows their way around Google, and learning how to find files via the Terminal is information easily found, even on Applehelpwriter! In short, all those methods listed above are really a waste of time if it’s security that you’re after.

Fortunately, there is a simple answer to securing localised files or folders, and that’s to make a local encrypted disk image with Disk Utility and then move your data into it. To do so, follow this procedure:

1. Open Disk Utility (Applications/Utilities/Disk

2. Click near the bottom of the sidebar in empty space to make sure none of the disks in the sidebar are selected.

3. Click the New Image icon in the task bar.

4. Give the image a name and choose a location to store it. Storing it in the User Library is not a bad idea. Give it a boring name like ‘old system’, ‘old data’ or something like that, but don’t hit ‘Create’ just yet.

5. At the bottom of the dialogue box is a field for encryption. Click on the option button and choose either 128-bit or 256-bit (the second choice is the strongest but also slower. 128-bit is still so strong that almost no-one save the CIA will be able to crack it!)

6. Create a password that you’re not going to forget. Do NOT use the same password that you use for your Admin account or for anything else for maximum security. Uncheck the ‘save in my keychain’ option.


if you forget the password don't waste time seeking help trying to break it. The system is designed to be uncrackable. If you forget the password, your data is lost for good.

PRO TIP: For that reason, you might like to use a password manager like ‘1Password‘ for this and all your other passwords. The main reason people forget passwords is infrequency of use. With 1Password you use a single password to unlock all your other passwords and to have them entered automatically into web pages and other fields.

7. Set up the rest of the options as in the screenshot below.

8. When you’re ready, press ‘Create’ to make the disk image.

9. Once the image has been created, copy the files you want to protect into the disk image window, just like you would a hard disk or other connected device. Now, whenever you want to access your protected data, just click on the disk image and enter the password and your data is ready to be used.

10. Test mounting and ejecting the disk image a few time. Open a few files and save your changes. After you’re sure everything is working as expected, delete the files from the original location that you copied them from. Also, don’t forget to eject the disk image in Finder’s sidebar each time when you’re done using it to prevent anyone else accessing your protected files.


uninstall flashback trojan

Among all the confusing posts and scare stories on offer this week about the flashback trojan, a lot of people seem to have missed the instructions for dealing with it.

Here’s F-Secure’s removal procedure:

uninstall trojan downloader

Here’s Rich Mogull’s general advice for securing your mac in light of this new threat:

What you need to know about the flashback trojan

It’s also worth emphasizing that, for technical reasons, if your mac has Microsoft Office 2008 or 2011 or Apple’s XCode installed, this particular trojan will not have been able to infect your computer.

%d bloggers like this: