Archive for Mac

How to Securely Dispose of Old Computers

How to Securely Dispose of Old Computers

Getting a computer can be exciting, but what happens to the old ones? Depending on the age, some people sell them, others throw them out. That’s the easy part – the problem is the sensitive data on them. There are passwords, account numbers, license keys, customer details, medical information, tax returns, browser history…. the works.

Whether it’s for home use or business use, laptops, tablets or desktop hard drives contain a treasure trove of sensitive information that cybercriminals would love to get their hands on. Unfortunately, hitting ‘delete’ on your files doesn’t actually make them disappear, nor does waving a strong magnet over the drive. These mistakes have cost businesses millions over the years.

Why hitting ‘delete’ doesn’t help

Data on a hard drive works like a book with an index page. Every time data is written, it pops a quick entry into the index so that when you need it again, it knows where to look. The index is used for files you create as well as system files you can’t even see. Sensible, right?

Except that if you delete a file it isn’t physically deleted – it’s more like changing the index to say that nothing is on page 10 and you can write something else there when you’re ready. But if you ignore the index and manually go to page 10, you’ll find that the information is still there – the file exists until it has been written over.

The only thing that is deleted is the index reference, not the file itself.

Re-using the computer

Most people are unaware that specialized data cleanup is necessary if the computer is to be reused.

A 2016 experiment proved just how dangerous the situation can be when 200 used ex-business hard drives were purchased and 67% held unwiped, unencrypted sensitive data, including sales projection spreadsheets, CRM records, and product inventories. Frighteningly, they didn’t need any special hacking skills to get this data, it was all right there and helpfully labelled.

It’s also not surprising that with simple data recovery tools, people have also been able to access British NHS medical records and defence data, all waiting patiently on a discarded hard drive.

Wiping data before re-use or selling

Data on a hard drive can only be securely deleted if the area on the drive that contains the data, has been overwritten enough. There are specialist tools available to ‘deep-read’ a drive, so the success of overwriting a drive depends on how effectively it has been overwritten.

For example the US Defence Department requires a drive to be overwritten a number of times, including using random characters, (not just ones and zeros as some programs use) before they class the drive as securely wiped.

There are software tools you can get to do it yourself, as well as dedicated security firms, but your best option is to choose an IT business you know and trust as some software does not clear the hard drive sufficiently. With that in mind, a methodical approach is required to ensure not a single drive is left untreated as you don’t want to leave data behind, or even clues that a motivated person could extrapolate any private information from.

We can migrate any needed data, backup the information then securely wipe or destroy the hard drives for you.

Data when disposing of a computer

When we supply new computers to homes or businesses, we copy the data from the old computer and transfer it into the new one, so things like documents, photos, even internet browser favourites are in the same place on the new machine, ready to use. But the old hard drive is still there, containing all the private data that you don’t want to allow into the wrong hands, so what is the best thing to do?

We give the customer a choice. We hand the customer the old hard drive so that they can either keep the drive securely at home, or at their business – not only can they be sure that the information is still secure but this has the added benefit of having a backup copy available, should it be needed.

Alternatively, they can simply destroy the drive and the rest of the old computer can just go for recycling. Computers need to be recycled as they contain metals such as lead, mercury and cadmium which is not intended for landfill or incineration. Also there are metals (including rare and precious metals) which can be recovered.

You don’t even need special equipment to destroy it, either smash the drive or use some other method of physically destroying it, such as drilling – just be very careful! If the drive is a mechanical one with spinning platters, once damaged beyond repair it is highly likely that no-one could get to your data.

Whether you are passing on, selling or just throwing away your old computer, always bear in mind that the hard drive inside it contains important and sensitive data, so you do need to make a decision about what to do with the drive.

Need help with your old hard drives? Give us a call on 01455 209505.

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 activity_agent.app 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.