A Reflection on the Waves Of Malice: Malicious File Distribution on the Web (part 2)

The first part of this article introduced the malicious file download dataset and the delivery network structure. This final part explores the types of files delivered, discusses how the network varies over time, and concludes with challenges for the research community.

The Great Divide: A PUP Ecosystem and a Malware Ecosystem

We found a notable divide in the delivery of PUP and malware. First, there is much more PUP than malware in the wild: we found PUP-to-malware ratios of 5:1 by number of SHA-2s, and 17:2 by number of raw downloads. Second, we found that mixed delivery mechanisms of PUP and malware are not uncommon (e.g., see our Opencandy case study in the paper). Third, the highly connected Giant Component is predominantly a PUP Ecosystem (8:1 PUP-to-malware by number of SHA-2s), while the many “islands” of download activity outside of this component are predominantly a Malware Ecosystem (1.78:1 malware-to-PUP by number of SHA-2s).

Comparing the structures of the two ecosystems,we found that the PUP Ecosystem leverages a higher degree of IP address and autonomous system (AS) usage per domain and per dropper than the Malware Ecosystem, possibly indicating higher CDN usage or the use of evasive fast-flux techniques to change IP addresses (though, given earlier results, the former is the more likely). On the other hand, the Malware Ecosystem was attributed with fewer SHA-2s being delivered per domain than the PUP Ecosystem with the overall numbers in raw downloads remaining the same, which could again be indicative of a disparity in the use of CDNs between the two ecosystems (i.e., CDNs typically deliver a wide range of content). At the same time, fewer suspicious SHA-2s being delivered per domain could also be attributable to evasive techniques being employed (e.g., malicious sites delivering a few types of files before changing domain) or distributors in this ecosystem dealing with fewer clients and smaller operations.

We tried to estimate the number of PPIs in the wild by defining a PPI service as a network-only component (or group of components aggregated by e2LD) that delivered more than one type of malware or PUP family. Using this heuristic, we estimated a lower bound of 394 PPIs operating on the day, 215 of which were in the PUP Ecosystem. In terms of proportions, we found that the largest, individual PPIs in the PUP and Malware Ecosystems involved about 99% and 24% of all e2LDs and IPs in their ecosystems, respectively.

With there being a number of possible explanations for these structural differences between ecosystems, and such a high degree of potential PPI usage in the wild (especially within the PUP Ecosystem), this is clearly an area in which further research is required.

Keeping Track of the Waves

The final part of the study involved tracking these infrastructures and their activities over time. Firstly, we generated tracking signatures of the network-only (server-side) and file-only (client-side) delivery infrastructures. In essence, this involved tracking the root and trunk nodes in a component, which typically had the highest node degrees, and thus, were more likely to be stable, as opposed to the leaf nodes, which were more likely to be ephemeral.

Continue reading A Reflection on the Waves Of Malice: Malicious File Distribution on the Web (part 2)

A Reflection on the Waves Of Malice: Malicious File Distribution on the Web (part 1)

The French cybercrime unit, C3N, along with the FBI and Avast, recently took down the Retadup botnet that infected more than 850,000 computers, mostly in South America. Though this takedown operation was successful, the botnet was created as early as 2016, with the operators reportedly making millions of euros since. It is clear that large-scale analysis, monitoring, and detection of malicious downloads and botnet activity, even as far back as 2016, is still highly relevant today in the ongoing battle against increasingly sophisticated cybercriminals.

Malware delivery has undergone an impressive evolution since its inception in the 1980s, moving from being an amateur endeavor to a well-oiled criminal business. Delivery methods have evolved from the human-centric transfer of physical media (e.g., floppy disks), sending of malicious emails, and social engineering, to the automated delivery mechanisms of drive-by downloads (malicious code execution on websites and web advertisements), packaged exploit kits (software packages that fingerprint user browsers for specific exploits to maximise the coverage of potential victims), and pay-per-install (PPI) schemes (botnets that are rented out to other cybercriminals).

Furthermore, in recent times, researchers have uncovered the parallel economy of potentially unwanted programs (PUP), which share many traits with the malware ecosystem (such as their delivery through social engineering and PPI networks), while being primarily controlled by different actors. However with some types of PUP, including adware and spyware, PUP has generally been regarded as an annoyance rather than a direct threat to security.

Using the download metadata of millions of users worldwide from 2015/16, we (Colin C. Ife, Yun Shen, Steven J. Murdoch, Gianluca Stringhini) carried out a comprehensive measurement study in the short-term (a 24-hour period), the medium-term (daily, over the course of a month), and the long-term (weekly, over the course of a year) to characterise the structure of this complex malicious file delivery ecosystem on the Web, and how it evolves over time. This work provides us with answers to some key questions, while, at the same time, posing some more and exemplifying some significant issues that continue to hinder security research on unwanted software activity.

An Overview

There were three main research questions that influenced this study, which we will traverse in the following sections of this post:

    1. What does the malicious file delivery ecosystem look like?
    2. How do the networks that deliver only malware, only PUP, or both compare in structure?
    3. How do these file delivery infrastructures and their activities change over time?

For full technical details, you can refer to our paper – Waves of Malice: A Longitudinal Measurement of the Malicious File Delivery Ecosystem on the Web – published by and presented at the ACM AsiaCCS 2019 conference.

The Data

The dataset was provided (and pre-sanitized) by Symantec and consisted of 129 million download events generated by 12 million users. Each download event contained information such as the timestamp, the SHA-2s of the downloaded file and its parent file, the filename, the size (in bytes), the referrer URL, Host URLs (landing pages after redirection) of the download and parent file, and the IP address hosting the download.

Continue reading A Reflection on the Waves Of Malice: Malicious File Distribution on the Web (part 1)

Beyond Regulators’ Concerns, Facebook’s Libra Cryptocurrency Faces another Big Challenge: The Risk of Fraud

Facebook has attracted attention through the announcement of their blockchain-based payment network, Libra. This won’t be the first payment system Facebook has launched, but what makes Facebook’s Libra distinctive is that rather than transferring Euros or dollars, the network is designed for a new cryptocurrency, also called Libra. This currency is backed by a reserve of nationally-issued currencies, and so Facebook hopes it will avoid the high volatility of cryptocurrencies like Bitcoin. As a result, Libra won’t be attractive to currency speculators, but Facebook hopes that it will, therefore, be useful for its stated goal – to be a “simple global currency and financial infrastructure that empowers billions of people.”

Reducing currency volatility is only one step towards meeting this goal of scaling cryptocurrencies to billions of users. The Libra blockchain design addresses how the network can maintain the high throughput and low transaction fees needed to compete with existing payment networks like Visa or MasterCard. However, a question that is equally important but as yet unanswered is how Facebook will develop a secure authentication and fraud prevention system that can scale to billions of users while maintaining good usability and low cost.

Facebook designed the Libra network, but in contrast to traditional payment networks, the Libra network is open. Anyone can send transactions through the network, and anyone can write programs (known as “smart contracts”) that control how, and under what conditions, funds can move between Libra accounts. To comply with anti-money-laundering regulations, Know Your Customer (KYC) checks will be performed, but only when Libra enters or leaves the network through exchanges. Transactions moving funds within the network should be accepted if they meet the criteria set out in the applicable smart contract, regardless of who sent them.

The Libra network isn’t even restricted to transactions transferring the Libra currency. Facebook has explicitly designed the Libra blockchain to make it easy for anyone to implement their own currency and benefit from the same technical facilities that Facebook designed for its currency. Other blockchains have tried this. For example, Ethereum has spawned hundreds of special-purpose currencies. But programming a smart contract to implement a new currency is difficult, and errors can be costly. The programming language for smart contracts within the Libra network is designed to help developers avoid some of the most common mistakes.

Facebook’s Libra and Securing the Calibra Wallet

There’s more to setting up an effective currency than just the technology: regulatory compliance, a network of exchanges, and monetary policy are essential. Facebook, through setting up the Libra Association, is focusing its efforts here solely on the Libra currency. The widespread expectation is, therefore, at least initially, the Libra cryptocurrency will be the dominant usage of the network, and most users will send and receive funds through the Calibra wallet smartphone app, developed by a Facebook subsidiary. From the perspective of the vast majority of the world, the Calibra wallet will be synonymous with Facebook’s Libra, and so damage to trust in Calibra will damage the reputation of Libra as a whole.

Continue reading Beyond Regulators’ Concerns, Facebook’s Libra Cryptocurrency Faces another Big Challenge: The Risk of Fraud

The Government published its draft domestic abuse bill, but risks ignoring the growing threat of tech abuse

Dr Leonie Tanczer, who leads UCL’s “Gender and IoT” research team, reflects on the release of the draft Domestic Abuse Bill and points out that in its current form, it misses emphasis on emerging forms of technology-facilitated abuse.

On the 21st of January, the UK Government published its long-awaited Domestic Abuse Bill. The 196-page long document focuses on a wide range of issues from providing a first statutory definition of domestic abuse to the recognition of economic abuse as well as controlling and coercive non-physical behaviour. In recent years, abuse facilitated through information and communication technologies (ICT) has been growing. Efforts to mitigate these forms of abuse (e.g. social media abuse or cyberstalking) are already underway, but we expect new forms of “technology-facilitated abuse” (“tech abuse”) to become more commonplace amongst abusive perpetrators.

We are currently seeing an explosion in the number of Internet-connected devices on the market, from gadgets like Amazon’s Alexa and Google’s Home hub, to “smart” home heating, lighting, and security systems as well as wearable devices such as smartwatches. What these products have in common is their networked capability, and many also include features such as remote, video, and voice control as well as GPS location tracking. While these capabilities are intended to make modern life easier, they also create new means to facilitate psychological, physical, sexual, economic, and emotional abuse as well as controlling and manipulating behaviour.

Although so-called “Internet of Things” (IoT) usage is not yet widespread (there were 7.5 billion total connections worldwide in 2017), GSMA expects there to be 25 billion devices globally by 2025. Sadly, we have already started to see examples of these technologies being misused. An investigation last year by the New York Times showed how perpetrators of domestic abuse could use apps on their smartphones to remotely control household appliances like air conditioning or digital locks in order to monitor and frighten their victims. In 2018, we saw a husband convicted of stalking after spying on his estranged wife by hacking into their wall-mounted iPad.

The risk of being a victim of tech abuse falls predominantly on women and especially migrant women. This is a result of men still being primarily in charge of the purchase and maintenance of technical systems as well as women and girls being over-proportionally affected by domestic abuse.

The absence of ‘tech abuse’ in the draft bill

While the four objectives of the draft Bill (promote awareness, protect and support, transform the justice process, improve performance) are to be welcomed, the absence of sufficient reference to the growing rise of tech abuse is a significant omission and missed opportunity.

Continue reading The Government published its draft domestic abuse bill, but risks ignoring the growing threat of tech abuse

UCL runs a digital security training event aimed at domestic abuse support services

In late November, UCL’s “Gender and IoT” (G-IoT) research team ran a “CryptoParty” (digital security training event) followed by a panel discussion which brought together frontline workers, support organisations, as well as policy and tech representatives to discuss the risk of emerging technologies for domestic violence and abuse. The event coincided with the International Day for the Elimination of Violence against Women, taking place annually on the 25th of November.

Technologies such as smartphones or platforms such as social media websites and apps are increasingly used as tools for harassment and stalking. Adding to the existing challenges and complexities are evolving “smart”, Internet-connected devices that are progressively populating public and private spaces. These systems, due to their functionalities, create further opportunities to monitor, control, and coerce individuals. The G-IoT project is studying the implications of IoT-facilitated “tech abuse” for victims and survivors of domestic violence and abuse.

CryptoParty

The evening represented an opportunity for frontline workers and support organisations to upskill in digital security. Attendees had the chance to learn about various topics including phone, communication, Internet browser and data security. They were trained by a group of so-called “crypto angels”, meaning volunteers who provide technical guidance and support. Many of the trainers are affiliated with the global “CryptoParty” movement and the CryptoParty London specifically, as well as Privacy International, and the National Cyber Security Centre.

G-IoT’s lead researcher, Dr Leonie Tanczer, highlighted the importance of this event in light of the socio-technical research that the team pursued so far: “Since January 2018, we worked closely with the statutory and voluntary support sector. We identified various shortcomings in the delivery of tech abuse provisions, including practice-oriented, policy, and technical limitations. We set up the CryptoParty to bring together different communities to holistically tackle tech abuse and increase the technical security awareness of the support sector.”

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Will new UK rules reduce the harm of push-payment fraud?

On Friday’s Rip off Britain I’ll be talking about new attempts by UK banks to prevent fraud, and the upcoming scheme for reimbursing the victims. While these developments have the potential to better protect customers, the changes could equally leave customers in a more vulnerable situation than before. What will decide between these two extremes is how well designed will be the rules surrounding these new schemes.

The beginning of this story is September 2016, when the consumer association – Which? – submitted a super-complaint to the UK Payment System Regulator (PSR) regarding push payment fraud – where a customer is tricked into transferring money into a criminal’s account. Such bank transfers are known as push payments because they are initiated by the bank sending the money, as opposed to pull payments, like credit and debit cards, where it is the receiving bank that starts the process. Banks claim that since the customer was involved in the process, they “authorised” the transaction, and so under UK and EU law, the customer is not entitled to a refund. I’ve argued that this interpretation doesn’t match any reasonable definition of the word “authorised” but nevertheless the term “authorised push payment scams” seems to have stuck as the commonly used terminology for this type of fraud, I’m sure much to the banks’ delight.

The Which? super-complaint asked for banks to be held liable for such frauds, and so reimburse the victims unless the bank can demonstrate the customer has acted with gross negligence. Which? argued that this approach would protect the customers from a fraud that exists as a consequence of bank design decisions, and provides banks with both a short-term incentive to prevent frauds that they can stop, as well as a medium-to-long term incentive for the banks to enhance payment systems to be resistant to fraud. The response from the PSR was disappointing, recognising that banks should do more, but rejecting the recommendation to hold banks liable for this fraud and requesting only that the banks collect more data. Nevertheless, the data collected proved useful in understanding the scale of the problem – £236 million stolen from over 42,000 victims in 2017, with banks only being able to recover 26% of the losses. This revelation led to Parliament asking difficult questions of the PSR.

The PSR’s alternative to holding banks liable for push payment fraud is for victims to be reimbursed if they can demonstrate they have acted with an appropriate level of care and that the bank has not. The precise definition of each level of care was a subject of consultation, and will now be decided by a steering group consisting of representatives of the banking industry and consumers. In my response to this consultation, I explained my reasons for recommending that banks be liable for fraud, including that fairly deciding whether customers met a level of care is a process fraught with difficulties. This is particularly the case due to the inequality in power between a bank and its customer, and that taking a banking dispute to court is ruinously expensive for most people since the option of customers spreading the cost through collective actions was removed from the Financial Services Act. More generally, banks – as the designers of payment systems and having real-world understanding of their use – have the greatest capacity to mitigate the risks these systems introduce.

Nevertheless, if the rules for the reimbursement scheme are set up well, it would be a substantial improvement over the current situation. On the other hand, if the process is bad then it could entrench the worst of current practices. Because the PSR has decided that reimbursement should depend on compliance to a level of care, my response also included what should be the process for defining these levels, and for adjudicating disputes.

Continue reading Will new UK rules reduce the harm of push-payment fraud?

Security code AutoFill: is this new iOS feature a security risk for online banking?

A new feature for iPhones in iOS 12 – Security Code AutoFill – is supposed to improve the usability of Two Factor Authentication but could place users at risk of falling victim to online banking fraud.

Two Factor Authentication (2FA), which is often referred to as Two Step Verification, is an essential element for many security systems, especially those online and accessed remotely. In most cases, it provides extended security by checking if the user has access to a device. In SMS-based 2FA, for example, a user registers their phone number with an online service. When this service sees a login attempt for the corresponding user account, it sends a One Time Password (OTP), e.g. four to six digits, to the registered phone number. The legitimate user then receives this code and is able to quote it during the login process, but an impersonator won’t.

In a recent development by Apple, announced at its developer conference WWDC18, they are set to automate this last step to improve user experience with 2FA with a new feature that is set to be introduced to iOS in version 12. The Security Code AutoFill feature, currently available to developers in a beta version, will allow the mobile device to scan incoming SMS messages for such codes and suggest them at the top of the default keyboard.

Description of new iOS 12 Security Code AutoFill feature (source: Apple)

Currently, these SMS codes rely on the user actively switching apps and memorising the code, which can take a couple of seconds. Some users deploy alternative try strategies such as memorising the code from the preview banner and hastily typing it down. Apple’s new iOS feature will require only a single tap from the user. This will make the login process faster and less error prone, a significant improvement to the usability of 2FA. It could also translate into an increased uptake of 2FA among iPhone users.

Example of Security Code AutoFill feature in operation on iPhone (source: Apple)

If users synchronise SMS with their MacBook or iMac, the existing Text Message Forwarding feature will push codes from their iPhone and enable Security Code AutoFill in Safari.

Example of Security Code AutoFill feature synchronised with macOS Mojave (source: Apple)

Reducing friction in user interaction to improve technology uptake for new users, and increase the usability and satisfaction for existing users, is not a new concept. It has not only been discussed in academia at length but is also a common goal within industry, e.g. in banking. This is evident in how the financial and payment industry has encouraged contactless (Near Field Communication – NFC) payments, which makes transactions below a certain threshold much quicker than traditional Chip and PIN payments.

Continue reading Security code AutoFill: is this new iOS feature a security risk for online banking?

Liability for push payment fraud pushed onto the victims

This morning, BBC Rip Off Britain focused on push payment fraud, featuring an interview with me (starts at 34:20). The distinction between push and pull payments should be a matter for payment system geeks, and certainly isn’t at the front of customers’ minds when they make a payment. However, there’s a big difference when there’s fraud – for online pull payments (credit and debit card)  the bank will give the victim the money back in many situations; for online push payments (Faster Payment System and Standing Orders) the full liability falls on the party least able to protect themselves – the customer.

The banking industry doesn’t keep good statistics about push payment fraud, but it appears to be increasing, with Which receiving reports from over 650 victims in the first two weeks of November 2016, with losses totalling over £5.5 million. Today’s programme puts a human face to these statistics, by presenting the case of Jane and Steven Caldwell who were defrauded of over £100,000 from their Nationwide and NatWest accounts.

They were called up at the weekend by someone who said he was working for NatWest. To verify that this was the case, Jane used three methods. Firstly, she checked caller-ID to confirm that the number was indeed the bank’s own customer helpline – it was. Secondly, she confirmed that the caller had access to Jane’s transaction history – he did. Thirdly, she called the bank’s customer helpline, and the caller knew this was happening despite the original call being muted.

Convinced by these checks, Jane transferred funds from her own accounts to another in her own name, having been told by the caller that this was necessary to protect against fraud. Unfortunately, the caller was a scammer. Experts featured on the programme suspect that caller-ID was spoofed (quite easy, due to lack of end-to-end security for phone calls), and that malware on Jane’s laptop allowed the scammer to see transaction history on her screen, as well as to listen to and see her call to the genuine customer helpline through the computer’s microphone and webcam. The bank didn’t check that the name Jane gave (her own) matched that of the recipient account, so the scammer had full access to the transferred funds, which he quickly moved to other accounts. Only Nationwide was able to recover any money – £24,000 – leaving Jane and Steven over £75,000 out of pocket.

Neither bank offered Jane and Steven a refund, because they classed the transaction as “authorised” and so falling into one of the exceptions to the EU Payment Services Directive requirement to refund victims of fraud (the other exception being if the bank believed the customer acted either with gross negligence or fraudulently). The banks argued that their records showed that the customer’s authentication device was used and hence the transaction was “authorised”. In the original draft of the Payment Services Directive this argument would not be sufficient, but as a result of concerted lobbying by Barclays and other UK banks for their records to be considered conclusive, the word “necessarily” was inserted into Article 72, and so removing this important consumer protection.

“Where a payment service user denies having authorised an executed payment transaction, the use of a payment instrument recorded by the payment service provider, including the payment initiation service provider as appropriate, shall in itself not necessarily be sufficient to prove either that the payment transaction was authorised by the payer or that the payer acted fraudulently or failed with intent or gross negligence to fulfil one or more of the obligations under Article 69.”

Clearly the fraudulent transactions do not meet any reasonable definition of “authorised” because Jane did not give her permission for funds to be transferred to the scammer. She carried out the transfer because the way that banks commonly authenticate themselves to customers they call (proving that they know your account details) was unreliable, because the recipient bank didn’t check the account name, because bank fraud-detection mechanisms didn’t catch the suspicious nature of the transactions, and because the bank’s authentication device is too confusing to use safely. When the security of the payment system is fully under control of the banks, why is the customer held liable when a person acting with reasonable care could easily do the same as Jane?

Another question is whether banks do enough to recover funds lost through scams such as this. The programme featured an interview with barrister Gideon Roseman who quickly obtained court orders allowing him to recover most of his funds lost through a similar scam. Interestingly a side-effect of the court orders was that he discovered that his bank, Barclays, waited more than 24 hours after learning about the fraud before they acted to stop the stolen money being transferred out. After being caught out, Barclays refunded Gideon the affected funds, but in cases where the victim isn’t a barrister specialising in exactly these sorts of disputes, do the banks do all they could to recover stolen money?

In order to give banks proper incentives to prevent push payment fraud where possible and to recover stolen funds in the remainder of cases, Which called for the Payment Systems Regulator to make banks liable for push payment fraud, just as they are for pull payments. I agree, and expect that if this were the case banks would implement innovative fraud prevention mechanisms against push payment fraud that we currently only see for credit and debit transactions. I also argued that in implementing the revised Payment Service Directive, the European Banking Authority should require banks provide evidence that a customer was aware of the nature of the transaction and gave informed consent before they can hold the customer liable. Unfortunately, both the Payment Systems Regulator, and the European Banking Authority conceded to the banking industry’s request to maintain the current poor state of consumer protection.

The programme concluded with security advice, as usual. Some was actively misleading, such as the claim by NatWest that banks will never ask customers to transfer money between their accounts for security reasons. My bank called me to transfer money from my current account to savings account, for precisely this reason (I called them back to confirm it really was them). Some advice was vague and not actionable (e.g. “be vigilant” – in response to a case where the victim was extremely cautious and still got caught out). Probably the most helpful recommendation is that if a bank supposedly calls you, wait 5 minutes and call them back using the number on a printed statement or card, preferably from a different phone. Alternatively stick to using cheques – they are slow and banks discourage their use (because they are expensive for them to process), but are much safer for the customer. However, such advice should not be considered an alternative to pushing liability back where it belongs – the banks – which will not only reduce fraud but also protect vulnerable customers.

Preventing phishing won’t stop ransomware spreading

Ransomware is in the news again, with Reckitt Benckiser reporting that disruption caused by the NotPetya ransomware could have cost them up to £100 million. In response to this news, just as every previous ransomware incident, the security industry started giving out advice – almost universally emphasising the importance of not opening phishing emails.

The problem is that this advice won’t work. Putting aside the fact that such advice is often so vague as to be impossible to put into action, the cause of recent ransomware outbreaks is not people opening phishing emails:

  • WannaCry, which notably caused severe disruption to the NHS, spread by automated scanning of computers vulnerable to an NSA-developed exploit. Although the starting point was initially assumed to be a phishing email, this was later debunked – only network scanning was used.
  • The Mole Ransomware attack that hit many organisations, including UCL, was initially thought to be spread by employees clicking on links in phishing emails. Subsequent analysis found this was incorrect and most likely the malware spread through malicious advertisements on legitimate websites.
  • NotPetya was initially thought to have been spread through Russian or Ukrainian phishing emails (explaining why that part of the world was so badly affected). It turned out to have not involved phishing at all, but the outbreak started through a tampered software update to the MEDoc tax accounting software mandated by the Ukranian government. Once inside an organisation, NotPetya then spread using the same exploit as WannaCry or by compromising administrative credentials.

Here are three major incidents, making international news, and the standard advice to “be vigilant” when opening emails or clicking links would have been useless. Is it any surprise that security advice gets ignored?

Not only is common anti-phishing advice unhelpful but it shifts blame to individuals (who are not in a position to prevent or mitigate most attacks) away from the IT industry and staff (who are). It also misleads management into thinking that they can “blame-and-train” their employees rather than investing in well engineered preventative security mechanisms and IT systems that can recover from compromise.

And there are things that can be done which have been shown to be effective, not just against the current outbreaks but many in the past and likely future. WannaCry would have been prevented by applying software updates, but the NotPetya outbreak was caused by a software update. The industry needs to act promptly to ensure that software updates are safe and reliable before customers become even more wary about installing them.

The spread of WannaCry and NotPetya within companies could have been prevented or slowed through better operational practices such as segmenting networks and limiting the use of administrative privilege. We’ve known this approach to be effective, but better tools and practices are needed to avoid enhanced security mechanisms being a drag on an organisation’s productivity.

Mole could have been prevented by ad-blocking browser extensions. The advertising industry is in open war against ad-blocking because it harms their income stream, but while they keep on spreading malware through their networks I have limited sympathy.

Well maintained and protected backups are essential to allow recovery, whether from ransomware, purely destructive attacks, or hardware failure. The security techniques above are effective, but these measures will not prevent every attack so mechanisms are needed to efficiently deal with the aftermath.

Most importantly we need to move away from security being a set of traditions passed from generation to generation with little or no reason to believe they are effective (so called “best practice”) to well engineered systems following rigorous, evidence-based guidance on state of the art cybersecurity principles, standards and practices.

Observing the WannaCry fallout: confusing advice and playing the blame game

As researchers who strive to develop effective measures that help individuals and organisations to stay secure, we have observed the public communications that followed the Wannacry ransomware attack of May 2017 with increasing concern. As in previous incidents, many descriptions of the attack are inaccurate – something colleagues have pointed out elsewhere. Our concern here is the advice being disseminated, and the fact that various stakeholders seem to be more concerned with blaming each other than with working together to prevent further attacks affecting organisations and individuals.

Countries initially affected in WannaCry ransomware attack (source Wikipedia, User:Roke)

Let’s start with the advice that is being handed out. Much of it is unhelpful at best, and downright wrong at worst – a repeat of what happened after Heartbleed, when people were advised to change their passwords before the affected organisations had patched their SSL code. Here is a sample of real advice sent out to staff in major organisation post-WannaCry:

“We urge you to be vigilant and not to open emails that are unexpected, unusual or suspicious in any way. If you experience any unusual computer behaviour, especially any warning messages, please contact your IT support immediately and do not use your computer further until advised to do so.”

Useful advice has to be correct and actionable. Users have to cope with dozens, maybe hundreds, of unexpected emails every day, most containing links and many accompanied by attachments, cannot take ten minutes to ponder each email before deciding whether to respond. Such instructions also implicitly and unfairly suggest that users’ ordinary behaviour plays a major role in causing major incidents like this one. RISCS advocates enlisting users as part of frontline defence. Well-targeted, automated blocking of malicious emails lessen the burden on individual users, and build resilience for the organisation in general.

In an example of how to confuse users, The Register reports that City of London Police sent out its “advice” via email in an attachment entitled “ransomware.pdf”. So users are simultaneously exhorted to be “vigilant” and not open emails and required to open an email in order to get that advice. The confusion resulting from contradictory advice is worse than the direct consequences of the attack: it enables future attacks. Why play Keystone Cyber Cops when UK National Technical Authority for such matters, the National Centre for Cyber Security, offers authoritative and well-presented advice on their website?

Our other concern is the unedifying squabbling between spokespeople for governments and suppliers blaming each other for running unsupported software, not paying for support, charging to support unsupported software, and so on, with and security experts weighing in on all sides. To a general public already alarmed by media headlines, finger-pointing creates little confidence that either party is competent or motivated to keep secure the technology on which our lives all now depend. When the supposed “good guys” expend their energy fighting each other, instead of working together to defeat the attackers, it’s hard to avoid the conclusion that we are most definitely doomed. As Columbia University professor Steve Bellovin writes, the question of who should pay to support old software requires broader collaborative thought; in avoiding that debate we are choosing to pay as a society for such security failures.

We would refer those looking for specific advice on dealing with ransomware to the NCSC guidance, which is offered in separate parts for SMEs and home users and enterprise administrators.

Much of NCSC’s advice is made up of things we all know: we should back up our data, patch our systems, and run anti-virus software. Part of RISCS’ remit is to understand why users often don’t follow this advice. Ensuring backups remain uninfected is, unfortunately, trickier than it should be. Ransomware will infect – that is, encrypt – not only the machine it’s installed on but any permanently-connected physical or network drive. This problem ought to be solved by cloud storage, but it can be difficult to find out whether cloud backups will be affected by ransomware, and technical support documentation often simply refers individuals to “your IT support”, even though vendors know few individuals have any. Dropbox is unusually helpful, and provides advice on how to recover from a ransomware attack and how far it can help. Users should be encouraged to read such advice in advance and factor it into backup plans.

There are many reasons why people do not update their software. They may, for example, have had bad experiences in the past that lead them to worry that security updates will fail or leave their system damaged, or incorporate unwanted changes in functionality. Software vendors can help here by rigorously testing updates and resisting the temptation to bundle in new features. IT support staff can help by doing their own tests that allow them to reassure their users that they will help resolve any resulting problems in a timely manner.

In some cases, there are no updates to install. The WannaCry ransomware attack highlighted the continuing use of desktop Windows XP, which Microsoft stopped supporting with security updates in 2014. A few organisations still pay for special support contracts, and Microsoft made an exception for WannaCry by releasing a security patch more widely. Organisations that still have XP-based systems should now investigate to understand why equipment using an unsafe, outdated operating system is still in use. Ideally, the software should be replaced with a more modern system; if that’s not possible the machine should be isolated from network connections. No amount of reminding users to patch their systems or telling them to “be vigilant” will be effective in such cases.

 

This article also appears on the Research Institute in Science of Cyber Security (RISCS) blog.