By now, even people who may never had heard of computer worms or ransomware have heard about #WannaCry. What just happened and how can these learnings help us better prepare our organisations for the next generation of attacks.
WannaCry is the largest ransomware infection in history with over 70 countries hit with an infection that encrypts the contents of Windows machines and demands bitcoin payment with the promise to unlock the file system and restore access to said files.
How did this happen?
On April 14th, 2017, a few weeks ago at time of writing, a group called Shadowbrokers dumped a bunch of internal software tools from the NSA. These are tools nation states create or purchase to exploit weaknesses in the software you know and use as part of an ongoing digital arms race.
Somehow, Shadowbrokers had managed to get hold of some of these bits and released them to the world — think of it as someone making off with weapons-grade plutonium and just giving it away.
This April 2017 dump included 3 groups of exploits, one related to data from the SWIFT payment network, a collection of documents and top secret PowerPoint presentations, and most interestingly, a care package of exploits for Windows machines. Some of these were exploits that had not been seen before and researchers fully expected to start seeing new attacks built on this, now public, knowledge.
WannaCry uses an exploit from this trove codenamed ETERNALBLUE & DoublePulsar to rapidly infect Windows machines on a network. Microsoft actually released MS17–010, a security update to fix this, in March. That was a good month before these NSA hacking tools were released to the public. However, at the time these updates were released only for their currently supported operating systems, as per normal commercial practice. We will come back to this.
What is happening now?
Luckily, as the infection broke a “kill switch” was discovered. A kill switch is often used to ensure that the creator has some control after the infection is out in the wild. At the very least, they typically want to ensure they can control it while they are actively creating or testing the malware so they do not demolish their own computers. In this instance, the kill switch was discovered to be a website that the software would check before it started about its business.
Security researchers quickly purchased the domain www.iuqerfsodp9ifjaposdfjhgosurijfaewrwergwea.com and it stopped computers that had internet access from further infection.
Microsoft has since released patches for these older operating systems to stem the tide. However, new versions of the worm are out with new kill switches including versions that have NO kill switch. It is clear that this isn’t over yet.
Why did this go so wrong?
To actually get across the organisation firewall and start spreading, WannaCry needed a backdoor into the system. The innovation for this worm was the use of phishing emails to get it onto the patient zero inside a network. This is the oldest trick in the book and it worked spectacularly well. Most organisations have such a poor posture with regards to their email cybersecurity that for a hacker, this is an obvious and relatively easy route to achieving an objective.
At the onset of the infection, the NHS in the UK was one of the most significant and public of the organisations affected as real people were put at risk.
We can check the relative health of an organisation’s email infrastructure from the outside by measuring the adoption of DMARC, an email cyber security standard. We did a review of domains belonging to around 200 NHS Authorities and Trusts and what we found shocked us.
Our hospitals are not only running unpatched, unsupported installations of the Windows operating system as evidenced by the scale of this infection, they have practically no protection to other email-borne threats as they fail to implement DMARC, something the NCSC describes as a fundamental cybersecurity protection. The one organisation listed who has DMARC is in the initial ‘reporting’ mode and currently receives no active protection from it.
WannaCry and its newly forming variants are still spreading and organisations need to clean up. Some variants appear to be dormant but replicating, so it is safe to say there is a lot of underreporting of the true extent of the problem. Some of these new variants are not created by the hackers behind the initial WannaCry ransomware so expect to see more takes on this type of attack in the near future. WannaCry isn’t even the only game in town right now, another ransomware dubbed Jaff was being spread at the rate of 5 million emails per hour when WannaCry broke out.
US-CERT, the American Computer Emergency team has been updating an alert on WannaCry and provide a section for Solutions and Recommended Steps for Prevention.
- The first thing they recommend you do is patch your system with the Microsoft patches to stop the spread.
- The second thing they recommended is using technology such as DMARC to prevent email spoofing and start reducing exposure to phishing.
Traditionally, DMARC has been complicated and expensive to deploy but we are working to change that. Our cloud service can test your email infrastructure and help you start your DMARC deployment in minutes.
Of course, the list of actions from US-CERT, including DMARC, isn’t a magic bullet. The reality is that this is one part of a system of tools and processes that need to be in play inside an organisation to ensure we don’t fall victim to an increasingly sophisticated and hostile cyber landscape. However, we should all be clear that the time for action is now.
Cybersecurity is now part of the cost of doing business, not just a procedure you invoke when things go wrong. It’s the difference between treatment and vaccination — when possible, prevention is far preferable to cleaning up after the epidemic. This should be a wake up call for businesses, governments, regulators and ordinary citizens.
Technology is a companion whose health and safety matters to the way we work, play and live our lives — we need to treat it as such.