Spear-phishing attacks are unstoppable. Every enhancement made towards filtering spam and phishing simply invites attackers to up their game even further. Years ago we learnt to avoid e-mails that looked dodgy and were full of spelling and grammatical errors. But then they grew more sophisticated: copying logos and house styles to look and read like genuine corporate announcements.
So we were taught to check the browser’s address bar to check that the loading web page was served over a valid HTTPS site. But now we face Punycode phishing attacks that play on tiny typographical differences between the Roman and other language alphabets: so even a trained typographer might be fooled by a fraudulent website.
Attackers operate at many layers, from amateurs to low-level professionals through to nation-state and specialist gangs highly focused on attacking specific targets – either for their financial value or their political sensitivity. At that upper level you find phishing emails that are truly unique, being tailored to snare just one specific individual – called 'patient zero’ in the industry – by including convincing personal details – favourite hobbies, activities or names of trusted friends – to make them look totally authentic. One click on that e-mail, and they have a foot in the door to your corporate network.
The Internet and e-mail have become so infected with malware that we have to give up hoping for any universal rule to nail down and identify every possible type of phishing email. Instead we are faced with an ever-expanding list of possible hacks to look out for, to the extent that employees might spend so much time taking precautions that they can no longer do their job thoroughly and efficiently.
So let us look at the problem from a new angle: comparing our malware-infected Internet to an infected water supply. If you learned that the tap water in your organization was contaminated, what would you do? You might begin by warning everybody, suggesting a few simple precautions such as not drinking the water unless it has been first boiled.
Would you then go on and on, broadcasting ever-more precautions: not to use any vessel or cutlery unless it has been washed in previously boiled water; not to wash your hands in un-boiled water; not to shake hands with anyone or touch a door handle or light switch without checking that no-one with contaminated hands has touched it… The list of possible precautions would be endless.
Or, having sounded that initial warning, would you simply take immediate steps to make sure the water will in future be filtered and sterilized before it enters the building?
This, basically, is the radical solution that was developed for the financial industry, and is now being taken up by other critical sectors across the globe – including government, technology, healthcare, oil and gas industries. It is a form of isolation technology called “DOM mirroring” that is delivered as a cloud service that ensures that only cyber-sterile e-mails, documents or websites can be accessed by employees on your network.
Education can only go so far
Yes, we must begin by increasing security awareness with basic training. But a typical employee cannot expect such training more than once or twice a year at best. Follow that up with posters and warnings about the increasing sophistication of phishing attacks – but people have other priorities and can easily forget and just get on with their work.
Even top anti-spam solutions will fail to detect the very cleverest spear-phishing emails. A brilliant sandbox may expose hundreds of threats – but it only takes one getting through to compromise the organisation’s security. The economic model is always in favour of the attacker: they can send hundreds of mails and it only needs that one to get through, whereas the defender needs the right thing to happen every time.
User-awareness and detection-based technologies only get you so far: after 20 years fighting this battle, there is no silver bullet to stop clever phishing emails hitting their target. So it is worth asking yourself how safe do you feel when reading this article? If you are reading it on a website, there might be any amount of malware lurking behind this page. The problem is that the Internet pleases its users by providing a rich, responsive multimedia experience – a far cry from the static pages of 20 years earlier.
All that responsiveness is possible because of the hidden “active content” that lies behind surface appearance – the Flash and Java and other interactive elements. Beneath that polished surface sophisticated attackers can play with combinations of browser types, versions, IP ranges, language settings and many other variables to trigger malware delivery or to block delivery of protection measures.
But perhaps you feel safe reading this article because you downloaded it as a PDF? Then you should know that PDF downloads are a very popular malware vector and even a Word document is a lot more complicated than it appears on the surface.
If, however, you are reading this article on paper, a printed copy, then you can feel pretty secure. Because there is absolutely nothing but the visible words, no hidden code to carry infection.
This points the way to a solution: would it be possible to isolate the browser so that it appears onscreen as a clean image without any good or bad software seething beneath the surface? And could this be done in real time?
The isolation solution
Browser isolation takes the radical step of assuming that any page – however innocent it seems or however reputable its source – might be infected. It assumes that no-one should ever trust a native web page, but should only work with a “safe page” reproduction – just like the printed page, but accessible and interactive on a normal screen.
The success of this approach depends on its ability to give the user as good an experience as an ordinary Internet browser. If it fell short by being slow, lower definition or relatively unresponsive, then productivity would suffer and users would simply risk using the original version. Any change in the appearance or behavior that forced users to change the way they work would be counter-productive: they would expect everyday operations such as copy-paste and printing to work just as normal.
“Pixel mirroring” was an early isolation approach. It treats the page as an array of pixels to be reproduced at the endpoint. The result is a one-size-fits-all approach that makes no allowance for the actual content – whether text, image or video – whereas the hidden active content is specifically designed to improve the user experience by adapting the rendering to suit the content. So pixel mirroring tends to slow down page loading, reduce responsiveness and elaborate common operations such as printing and copy-paste.
The newer approach takes into account the actual content type and the dynamic manner it is represented in the browser – ie the “Document Object Model” (DOM). “DOM Mirroring” actively monitors the page tab for changes, translates those changes into DOM commands (without the underlying active content) and sends those commands to the end user’s device, so the safe page automatically updates in sync with the original.
So, for example, instead of sending a Flash video to the end point, the same movie will be sent as crisp, suitable quality HTML5, while non-active safe elements are simply transmitted as they are. All the natively available fonts and images can be safely transmitted to the end-user‘s browser whilst being sanitized to prevent font & image exploits to be used. The whole page still looks, feels and behaves just as it should, but it is now safe.
When it comes to installing isolation technology, you do not want the complexity of extra software, hardware or endpoints to manage. So the best isolation platform sits in the cloud as a service. Instead of needing to buy and roll out extra hardware or software, this cloud service can be immediately accessed across the organisation – include smartphones and personal devices – and can be kept constantly up-to-date and centrally managed without adding to the IT burden.
Instead of yet another security training session, why not ask for a demonstration of the power of isolation? The worldwide user response has been uniformly positive – notably in the highly critical and time conscious financial sector.
The DOM mirroring isolation platform was first developed in collaboration with JPMorgan Chase & Co and, according to their Chief Information Security Officer, Rohan Amin, the platform was deployed “with zero impact to users, providing a seamless user experience for our employees”. Since then it has been successfully adopted by many organisations worldwide, and it is already supported by teams in the United States, UK, Germany, Japan, Singapore and Australia to meet the growing demand.
The common factor among all the early adopters has been the need for constant Internet access, combined with serious concern about the attendant risks. They find that a cloud-based isolation service is easily and quickly deployed, without any disruption of normal working patterns. The users like it, and the reduction in risk is boosting both morale and productivity.
Yes, basic security training is a vital first step. But it has to be admitted that most employees’ first priority is their daily workload, rather than cyber security. You can only go so far with education – after that you should insist on isolation technology.
Spear-phishing isn’t going to go away; it’s simply too effective. Nowadays it makes much more sense to purify your water – and your communications – before they reach your employees.
Article by Jason Steer, CTO EMEA at Menlo Security.