Archive for Mac

Spectre and Meltdown – What They Mean for You

Modern computers contain processors (CPUs) which do the heavy calculations that make your device work – the better the CPU, the faster your device. These computer chips are used in devices made by computer manufacturers all over the world, as well as Microsoft, Apple, Google and are in servers everywhere.

‘Spectre’ and ‘Meltdown’

Severe design flaws were recently discovered in CPUs, and these vulnerabilities were called ‘Spectre’ and ‘Meltdown’. Essentially these vulnerabilities can allow hackers to take advantage of the fact that whilst it is not being fully used, modern CPUs can do something called ‘speculative execution’. This is a techy way of saying that they take notice of what tasks you do often, and try to do those tasks for you in the background and store the data for you, so that it is quicker for you then next time you choose to do that task.

It’s a bit like going to the same coffee shop every day and one day you find that they have your cup ready for you. Except in this case instead of coffee its data – at times very important data – and that’s the problem. This data is held in something called a ‘cache’ and just sits there until it is told to clear itself.

The ‘Spectre’ vulnerability allows attackers to trick the processor into performing these speculative operations and ‘Meltdown’ can collect the data that is created. To date there have been no reports of attacks but as this has been known in the IT community for a while it is only a matter of time, especially given the fact that these vulnerabilities exist in CPUs made over very many years – so there are plenty of them to attack.

It is serious enough that CPU makers and makers of Operating Systems are rushing to get security fixes out to users. Intel are issuing updates for their processors to fix the vulnerability and AMD are working on a patch. Microsoft have issued updates for Windows 7, 8.1 and 10, with Apple have released updates for iOS11.2, MacOS 10.13.2 and tvOS 11.2. Google, Amazon etc. are also looking at the issue.

What does it actually mean for you?

The fixes that are being issued make changes to the way CPUs speed up your work – in effect the fixes are putting the brakes on the CPU to an extent and potentially reducing its performance. Some people may see a minimal impact but some may see a significant slowdown in the performance of their device after the fixes have been applied.

At the present time, it is believed that Windows 10 with newer CPUs will see a negligible impact but with older CPUs there may be a noticeable decrease in performance. Most noticeable decrease in performance are Windows 7 and 8 machines with older CPUs and according to Microsoft, fixes for Windows Servers will have a “significant impact” on performance after the updates.

It may be that over time, these updates may be refined and the impact may be reduced, but for the time being if you see a marked decrease in the performance of your device, it may well be that fixes for CPU flaws are causing it or contributing to it.

Whilst it may be unwelcome news, it is vital that you do keep all your updates current, no matter what device you are using.

If you would like help please call us on 01455 209505.

Mac Computers and Viruses – Truth versus Myth

Compromised app containing a virus

We have lost count of the number of times that we’ve heard the phrase “Macs don’t get viruses” or “I’ve never had protection on my Mac”. Whilst this may have been true in the past it isn’t as cut and dried today and the Mac OSX operating system actually can be vulnerable, so protection is worth seriously considering especially in a work or business situation.

More difficult to exploit

The Mac is based on the UNIX operating system (as is Linux) which is more difficult to exploit as it is built on a sandbox-type principle, where malicious code cannot usually get as far as it might get in a non-UNIX based system.  Also, Apple has built in a certain degree of malware prevention in the Mac, for example their ‘Gatekeeper’ software actually blocks apps that have been downloaded from the internet (i.e. anywhere other than the Apple Store) that do not have a Developer ID supplied by Apple certifying that they are safe to use.

Unfortunately, in spite of this robustness the Mac is now becoming a victim of its own success because its increasing popularity means that cybercriminals are paying more attention to it – and finding ways of making money from you even if you are a Mac user. It’s not just that popularity – Macs are usually much more expensive to buy, so the cybercriminals may believe that Mac users are attractive targets.

Not impossible to exploit

For example, a popular Mac DVD-ripping and Video Conversion app called ‘Handbrake’ was recently compromised, by criminals hacking the software company download server and inserting malicious code into the app download. When this download was installed on a Mac, it also installed a ‘backdoor’ (a means of bypassing security). The user then was asked for their administrator password, which was passed over the internet in plain text so that the criminals could access any part of the system from that point.

By successfully avoiding having to use the ‘direct attack’ approach, this allowed important information such as password keychains and browser data to be extracted and passed to the crooks.

This compromise has now been corrected and the infected code was from a download between 2nd and 6th May 2017. If you have installed Handbrake version 1.0.7, check the SHA1 checksum of the file by opening a Terminal, typing in shasum and dragging the installation file into the Terminal Window.

If the checksum is 0935a43ca90c6c419a49e4f8f1d75e68cd70b274 then the file is malicious.

To disinfect it remove the Launch Agent plist file fr.handbrake.activity_agent.plist, and the file located in ~/Library/RenderFiles/. Reboot then change your passwords.

In the past year or so a Ransomware-type malware was discovered for the Mac, so this isn’t the first time that there has been a potential issue.

Even though the Mac is more robust and secure than its main competitor, it is by no means invulnerable to malicious code and it is a risk to think otherwise. You may feel that the risk is small enough to continue to use your Mac as you always have, but at least consider the pros and cons first – as well as being very careful about where you get your apps from.

If you would like help in securing your Mac, give us a call on 01455 209505.