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.

PayBreak able to defeat WannaCry/WannaCryptor ransomware

Recently I worked on some research with colleagues at Boston University (Manuel Egele, William Koch) and University College London (Gianluca Stringhini) into defeating ransomware. The fruit of our labor, PayBreak published this year in ACM ASIACCS, is a novel proactive system against ransomware. It happens to work against the new global ransomware threat, WannaCry. WannaCry is infecting more than 230,000 computers in 150 countries demanding ransom payments in exchange for access to precious files. This attack has been cited as being unprecidented, and the largest to date. Luckily, our research works against it.

PayBreak works by storing all the cryptographic material used during a ransomware attack. Modern ransomware uses what’s called a “hybrid cryptosystem”, meaning each ransomed file is encrypted using a different key, and each of those keys are then encrypted using another private key held by the ransomware authors. When ransomware attacks, PayBreak records the cryptographic keys used to encrypt each file, and securely stores them. When recovery is necessary, the victim retrieves the ransom keys, and iteratively decrypts each file.

Defeating WannaCry Ransomware

At this point, I think I’ve reverse engineered and researched something like 30 ransomware families, from over 1000 samples. Wannacry isn’t really much different than every other ransomware family. Those include other infamous families like Locky, CryptoWall, CryptoLocker, and TeslaLocker.

They all pretty much work the same way, including Wannacry. Actually, this comic sums up the ransom process the best I’ve seen. Every successful family today encrypts each file for ransom with a new unique “session” key, and encrypts each session key with a “private” ransom key. Those session keys are generated on the host machine. This is where PayBreak shims the generation, and usage of those keys, and saves them. Meaning, the encryption of those session keys by the ransomware’s private key is pointless, and defeated.

The PayBreak system doesn’t rely on any specific algorithm, or cryptographic library to be used by ransomware. Actually, Wannacry implemented, or atleast, statically compiled its own AES-128-CBC function. PayBreak can be configured to hook arbitrary functions, including that custom AES function, and record the parameters, such as the key, passed to it. However, a simpler approach in this case was to hook the Windows secure pseudorandom number generator function, CryptGenRandom, which the ransomware (and most others) use to create new session keys per file, and save the output of the function calls.

Recovering files is simply testing each of the recorded session keys with the encrypted files, until a successful decryption. Decrypting my file system of ~1000 files took 94 minutes.

Encrypted: Desert.jpg.WNCRY
Key used by Wannacry: cc24d9c8388fa566456ccec745e009c8
Decrypted: Desert.jpg

Thanks @jeffreycrowell for sharing a sample with me.
The full paper can be found here: https://eugenekolo.com/static/paybreak.pdf
SHA256 Hash of Sample: 24d004a104d4d54034dbcffc2a4b19a11f39008a575aa614ea04703480b1022c
WannaCry Custom AES: https://gist.github.com/eugenekolo/fe229be2a4230cf8322bf5537e291812

 

The original post appeared on Eugene Kolodenker’s blog.

The politics of the NHS WannaCrypt ransomware outbreak

You know you live in 2017 when the top headline on national newspapers relates to a ransomware attack on the National Heath Service, the UK Prime minister comments on the matter, and the the security researchers dealing with the outbreak are presented as heroic figures. As ever, The Register, has the most detailed and sophisticated technical article on the matter. But also strangely the most informative in terms of public policy. As if somehow, in our days, technical sophistication is a prerequisite also for sophisticated political comment on those matters. Other news outlets present a caricature, of the bad malware authors, the good security researcher and vendors working around the clock, the valiant government defenders, and a united humanity trying to beat the virus. I want to break that narrative open in this article, and discuss the actual political and social lessons we should be learning. In part to avoid similar disasters in the future.

First off, I am always surprised when such massive systemic outbreaks of malware, are blamed squarely on the author(s) of the malware itself, and the blame game ends there. It is without doubt that the malware author has a great share of responsibility. I personally think it is immoral to deploy ransomware in the wild, deny people access to their data, and seek to benefit from this. It is also a crime in the UK and elsewhere.

However, it is strange that a single author, or a small group of authors, without any major resources can have such a deep and widespread effect on major technological infrastructures. The absurdity becomes clear if we transpose the situation into the world of traditional engineering. Imagine all skyscrapers in major cities had to be evacuated, because a couple of teenagers with rocks were trying to blackmail business owners to pay up, to protect their precious glass windows. The fragility of software and IT systems seems to have no parallel in any other large scale engineering infrastructure — and this is not inherent, but the result of very specific micro-political, geo-political and economic decisions.

Lets take the WannaCrypt outbreak and look at the political and other social decisions that lead to the disaster — besides the agency of the malware authors:

  • The disaster was possible in part, and foremost, because IT systems within the UK critical NHS infrastructure are outdated — and for example rely on Windows XP that is not any more being maintained by Microsoft. Well, actually this is not strictly true: Microsoft does make security updates for Windows XP, but does not provide them for free — and instead Microsoft expects organizations that are locked in the OS to pay up to get patches and stay safe. So two key questions need to be asked …
  • Why is the NHS not upgrading to a new versions of Windows, or any other modern operating system? The answer is simple: line of business applications (LOB: from heath record management, specialist analysis and imaging software, to payroll) may not be compatible with new operating systems. On top of that a number of modern medical devices, such as large X-ray scanners or heart monitors, come with embedded computers running Windows XP — and only Windows XP. There is no way of upgrading them. The MEDJACK cyber-attacks were leveraging this to rampage through hospitals in 2015.
  • Is having LOB software tying you to an outdated OS, or medical devices costing millions that are not upgradeable, a fact of nature? No. It is down to a combination of terrible and naive procurement processes in health organizations, that do not take into account the need and costs if IT and security maintenance — and do not entrench it into the requirements and contracts for services, software and devices. It is also the result of the health software and devices industries being immature and unsophisticated as to the needs to secure IT. They reap the benefits of IT to make money, but without expending much of it to provide quality and security. The tragic state of security of medical devices has built the illustrious career of my friend Prof. Kevin Fu, who has found systemic attacks against implanted heart devices that could kill you, noob security bugs in medical device software, and has written extensively on the poor strategy to tackle these problem. So today’s attacks were a disaster waiting to happen — and expect more unless we learn the right lessons.
  • So given the terrible state of IT that prevents upgrading the OS, why is the NHS not paying up Microsoft to get security patches? That is because the government, and Jeremy Hunt in particular, back in 2014 decided to not pay up the money necessary to keep receiving security updates for Windows XP, despite being aware of the absolute reliance of the NHS on the outdated software. So in effect, a deliberate political decision was taken, at the highest level of the government to leave the NHS open to cyber attack. This is unlikely to be the last Windows XP security bug, so more are presumably to come.
  • Then there is the question of how malware authors, managed to get access to security bugs for windows XP? How did they get the tools necessary to attack such a mature, and rather common system, about 15 years after Windows XP was released, and only after it went out of maintenance? It turn out that the vulnerabilities they used, were in fact hoarded by the NSA as a cyber weapon — which was lost or stolen by hackers or leakers, and released into the wild! (The tool was codenamed EternalBlue). For may years, the computer security research community has been warning that stockpiling vulnerabilities in very common software for cyber-offense purposes, is dangerous. When those cyber weapons are lost, leaked, or even just used, there is proliferation of the technology necessary to attack, which criminals and foreign states can turn against critical infrastructure. This blog commented on the matter as recently as 8 March 2017 in a post entitled “What the CIA hack and leak teaches us about the bankruptcy of current “Cyber” doctrines”. This now feels like an unfortunately fulfilled prophesy, but the NHS attack was just the expected outcome of the US/UK and now common place doctrine around cyber — that contributes to, and leverages insecurity rather than security. Alternative public policy options exist of course.

So to summarize, besides the author of the malware, a number of other social and systemic factors contribute to making such cyber attacks possible: from poor security standards in heath informatics industries; poor procurement processes in heath organizations; lack of liability on any of the software vendors (incl. Microsoft) for providing insecure software or devices; cost-cutting from the government on NHS cyber security with no constructive alternatives to mitigate risks; and finally the UK/US cyber-offense doctrine that inevitably leads to proliferation of cyber-weapons and their use on civilian critical infrastructures.

It it those systemic factors that need to change to avoid future failures. Bad people wishing to make money from ransomware, or other badness, will always exist. There is a discipline devoted to preventing this, and it is called security engineering. It is time industry and goverment start taking its advice seriously.

 

This was originally posted on Conspicuous Chatter, the blog of Prof. George Danezis.

Underground abraCARDabra: Understanding carding forums

Paying for dinner? A taxi ride? A tropical drink? Sure. Swipe or tap your card and it is done. Convenient. Payment cards make it easy for us to make payments at “brick-and-mortar” locations and online marketplaces. However, they are also attractive targets for cybercriminals seeking to steal funds from the accounts linked to payment cards, as seen in this recent high-profile theft of credit cards affecting more than 1,000 hotels, for instance.

Theft of payment card information via phishing, skimming, or hacking, is usually the first step in the chain of payment card fraud. Other steps include sales, validation, and monetisation of the stolen data. These illicit deals are aided by underground online forums where cybercriminals actively trade stolen credit card information. To tackle payment card fraud, it is therefore important to understand the characteristics of these forums and the activity of miscreants using them. In our paper, presented at the 2017 APWG Symposium on Electronic Crime Research (eCrime2017), we analyse and discuss the characteristics of underground carding forums. We focus on the available products and prices, characteristics of sellers, and features of the forums. We won the Best Paper Award at eCrime2017.

Products

The main products available on carding forums are credit card numbers, dumps, and fullz. Credit card numbers comprise the information actually printed on credit cards, that is, cardholder name, card number (16 digits on most cards), expiry date, and the security code on the back of the card (usually 3 digits).

Dumps comprise stolen information from the tracks of magnetic stripe of a credit card. Dumps are usually obtained via skimmers. Skimmers are devices attached to Automated Teller Machines (ATMs) and Point of Sale (POS) terminals by miscreants to steal data from unsuspecting victims. Afterwards, the miscreants create clones of the skimmed credit cards and monetise the clones, for instance, by making illicit purchases with them.

Fullz contain further information about the cardholder. In other words, fullz usually comprise information printed on the card plus additional information such as bank account information, cardholder’s date of birth, Social Security number, etc.

Sellers

Generally, there are several types of participants on carding forums: sellers, buyers, intermediaries, mules, administrators, and others. These roles are not mutually exclusive; sellers may simultaneously be buyers. In this study, we focus on sellers since they come before buyers in the fraud chain.

Our approach

We studied previous work on underground marketplaces and forums, and derived the following hypotheses from the insights gained. We then searched for names of carding forums, found 25 names, and collected data from 5 active forums. We then tested the hypotheses on the data.

Hypothesis 1. Prices of fullz (credit card numbers and additional cardholder information) are higher than prices of credit card numbers.
Hypothesis 2. A small number of traders are responsible for a large
proportion of traffic.
Hypothesis 3. Most traders sell only one product type (that is, they are specialised).
Hypothesis 4. Specialised traders sell their products at lower prices than unspecialised traders.
Hypothesis 5. Carding forums have working reputation systems that are as sophisticated as those of legal marketplaces (for instance, eBay).
Hypothesis 6. The vast majority of actors do not operate on more than
one forum.

Summary of findings

Our analyses confirmed Hypothesis 1, Hypothesis 2, and Hypothesis 6. In other words, prices of fullz are indeed higher than prices of credit card numbers (credit card numbers: mean = $10.08, median = $10.00; fullz: mean = $31.82, median = $30.00). Also, a small number of traders are responsible for a large proportion of traffic. Finally, most sellers focus their efforts on a single forum, as expected.

Hypothesis 4 was partially rejected, while Hypothesis 3 and Hypothesis 5 were completely rejected. In other words, specialised sellers do not always sell their products at lower prices than the unspecialised ones, most sellers advertise more than one type of product, and most of the carding forums under study do not have working reputation systems that are as elaborate as those of legitimate online marketplaces.

In conclusion, dumps and fullz are relatively expensive; they are more than three times as expensive as credit card numbers. This may be due to the effort needed to obtain or monetise the data, the amount of available information, or differing supply and demand. Sellers have varying success. Even though some sellers complete hundreds of transactions, most sellers do not succeed in selling anything. This means that the trading sections of the forums are profitable distribution channels for high-profile actors. Finally, specialisation is not a key characteristic of sellers, not even of high-profile sellers.

Further details can be found in the full paper All Your Cards Are Belong To Us: Understanding Online Carding Forums, by Andreas Haslebacher, Jeremiah Onaolapo, and Gianluca Stringhini.

Online security won’t improve until companies stop passing the buck to the customer

It’s normally in the final seconds of a TV or radio interview that security experts get asked for advice for the general public – something simple, unambiguous, and universally applicable. It’s a fair question, and what the public want. But simple answers are usually wrong, and can do more harm than good.

For example, take the UK government’s Cyber Aware scheme to educate the public in cybersecurity. It recommends individuals choose long and complex passwords made out of three words. The problem with this advice is that the resulting passwords are hard to remember, especially as people have many passwords and use some infrequently. Consequently, they will be tempted to use the same password on multiple websites.

Password re-use is far more of a security problem than insufficiently complex passwords, so advice that doesn’t help people manage multiple passwords does more harm than good. Instead, I would recommend remembering your most important passwords (like banking and email), and store the rest in a password manager. This approach isn’t perfect or suitable for everyone, but for most people, it will improve their security.

Advice unfit for the real world

Cyber Aware also tells people not to write down their passwords, or let anyone else know them – banks require the same thing. But we know that people commonly share their banking credentials with family, for legitimate reasons. People also realise that writing down passwords is a pretty good approach if you’re only worried about internet hackers, rather than people who can get close to you to see the written notes. Security advice that doesn’t stand up to scrutiny or doesn’t fit with people’s lives will be ignored – and will discredit the organisation offering it.

Because everyone’s situation is different, good security advice should include helping people to understand what risks they should be worried about, and to take steps that mitigate these risks. This advice doesn’t have to be complicated. Teen Vogue published a tutorial on how to select and configure a secure messaging tool, which very sensibly explains that if you are more worried about invasions of privacy from people who can get their hands on your phone, you should make different choices than if you are just concerned about, for example, companies spying on you.

The Teen Vogue article was widely praised by security experts, in stark contrast to an article in The Guardian that made the eye-catching claim that encrypted messaging service WhatsApp is insecure, without making clear that this only applies in an obscure and extremely unlikely set of circumstances.

Zeynep Tufekci, a researcher studying the effects of technology on society, reported that the article was exploited to legitimise misleading advice given by the Turkish government that WhatsApp is unsafe, resulting in human rights activists using SMS instead – which is far easier for the government to censor and monitor.

The Turkish government’s “security advice” to move from WhatsApp to less secure SMS was clearly aimed more at assisting its surveillance efforts than helping the activists to whom the advice was directed. Another case where the advice is more for the benefit of the organisation giving it is that of banks, where the terms and conditions small print gives incomprehensible security advice that isn’t true security advice, instead merely a legal technique to allow the banks wiggle room to refuse to refund victims of fraud.

Continue reading Online security won’t improve until companies stop passing the buck to the customer

What the CIA hack and leak teaches us about the bankruptcy of current “Cyber” doctrines

Wikileaks just published a trove of documents resulting from a hack of the CIA Engineering Development Group, the part of the spying agency that is in charge of developing hacking tools. The documents seem genuine and catalog, among other things, a number of exploits against widely deployed commodity devices and systems, including Android, iPhone, OS X and Windows. Also smart TVs. This hack, with appropriate background, teaches us a lesson or two about the direction of public policy related to “cyber” in the US and the UK.

Routine proliferation of weaponry and tactics

The CIA hack is in many ways extraordinary, in that it allowed the attackers to gain access to the source code of the hacking tools of the agency – an extraordinary act of proliferation of attack technologies. In other ways, it is mundane in that it is neither the first, nor probably the last hack or leak of catastrophic proportions to occur to a US/UK government department in charge of offensive cyber operations.

This list of leaks of government attack technologies, illustrates that when it comes to cyber-weaponry the risk of proliferation is not merely theoretical, but very real. In fact it seems to be happening all the time.

I find it particularly amusing – and those in charge of those agencies should probably find it embarrassing – that NSA and GCHQ go around presenting themselves as national technical authorities in assurance; they provide advice to others on how to not get hacked; they keep asserting that they can be trusted to operate extremely dangerous spying infrastructures; and handle in secret extremely dangerous zero-day exploits. Yet, they seem to be routinely hacked and have their secret documents leaked. Instead of chasing whistleblowers and journalists, policy makers should probably take note that there is not a high-enough level of assurance to secure cyber-weaponry, and for sure it is not to be found within those agencies.

In fact the risk of proliferation is at the very heart of cyber attack, and integral to it, even without hacking or leaking from inside government. Many of us quietly laughed at the bureaucratic nightmare discussed in the recent CIA leak, describing the difficulty of classifying the cyber attack techniques while at the same time deploying them on target system. As the press release summarizes:

To attack its targets, the CIA usually requires that its implants communicate with their control programs over the internet. If CIA implants, Command & Control and Listening Post software were classified, then CIA officers could be prosecuted or dismissed for violating rules that prohibit placing classified information onto the Internet. Consequently the CIA has secretly made most of its cyber spying/war code unclassified.

This illustrates very clearly a key dynamic in hacking: once a hacker uses an exploit against an adversary system, there is a very real risk the exploit is captured by monitoring and intrusion detection systems of the target, and then weponized to hack other computers, at a low cost. This is very well established and researched, and such “honey pot” infrastructures have been used in the academic and commercial community for some time to detect and study potentially new attacks. This is not the premise of sophisticated defenders, the explanation of how honeypots work is on Wikipedia! The Flame malware, and Stuxnet before, were in fact found in the wild.

In that respect cyber-war is not like war at all. The weapons you use will be turned against you immediately, and your effective use of weapons relies on your very own infrastructures being utterly vulnerable to them.

What “Cyber” doctrine?

The constant leaks and hacks, leading to proliferation of exploits and hacking tools from the heart of government, as well through operations, should deeply inform policy makers when making choices about “cyber” doctrines. First, it is probably time to ditch the awkward term “Cyber”.

Continue reading What the CIA hack and leak teaches us about the bankruptcy of current “Cyber” doctrines

Security intrusions as mechanisms

The practice of security often revolves around figuring out what (malicious act) happened to a system. This historical inquiry is the focus of forensics, specifically when the inquiry regards a policy violation (such as a law). The results of forensic investigation might be used to fix the impacted system, attribute the attack to adversaries, or build more resilient systems going forwards. However, to execute any of these purposes, the investigator first must discover the mechanism of the intrusion.

As discussed at an ACE seminar last October, one common framework for this discovery task is the intrusion kill chain. Mechanisms, mechanistic explanation, and mechanism discovery have highly-developed meanings in the biological and social sciences, but the word is not often used in information security. In a recent paper, we argue that incident response and forensics investigators would be well-served to make use of the existing literature on mechanisms, as thinking about intrusion kill chains as mechanisms is a productive and useful way to frame the work.

To some extent, thinking mechanistically is a description of what (certain) scientists do. But the mechanisms literature within philosophy of science is not merely descriptive. The normative benefits extolled include that thinking mechanistically is an effective heuristic for searching out useful explanations; mechanisms provide the most coherent unity to complex fields of study; and that mechanistic explanation is necessary to guide selection among potential studies given limited experimental resources, experiment design decisions, and interpretation of statistical results. I previously argued that capricious use of biological metaphors is bad for information security. We are keenly aware that these benefits of mechanistic explanation need to apply to security as and for security, not merely because they work in other sciences.

Our paper demonstrates how we can cast the intrusion kill chain, the diamond model, and other models of security intrusions as mechanistic models. This casting begins to demonstrate the mosaic unity of information security. Campaigns are made up of attacks. Attacks, as modeled by the kill chain, have multiple steps. In a specific attack, the delivery step might be accomplished by a drive-by-download. So we demonstrate how drive-by-downloads are a mechanism, one among many possible delivery mechanisms. This description is a schema to be filled in during a particular drive-by download incident with a specific URL and specific javascript, etc. The mechanistic schema of the delivery mechanism informs the investigator because it indicates what types of network addresses to look for, and how to fit them into the explanation quickly. This process is what Lindley Darden calls schema instantiation in the mechanism discovery literature.

Our argument is not that good forensics investigators do not do such mechanism discovery strategies. Rather, it is precisely that good investigators do do them. But we need to describe what it is good investigators in fact do. We do not currently, and that lack makes teaching new investigators particularly difficult. Thinking about intrusions as mechanisms unlocks an expansive literature on good ways to do mechanism discovery. This literature will make it easier to codify what good investigators do, which among other benefits allows us to better teach sound methodological practices to incoming investigators.

Our paper on this topic was published in the open-access Journal of Cybersecurity, as Thinking about intrusion kill chains as mechanisms, by Jonathan M. Spring and Eric Hatleback.

A Longitudinal Measurement Study of 4chan’s Politically Incorrect Forum and its Effect on the Web

The discussion board site 4chan has been a part of the Internet’s dark underbelly since its creation, in 2003, by ‘moot’ (Christopher Poole). But recent events have brought it under the spotlight, making it a central figure in the outlandish 2016 US election campaign, with its links to the “alt-right” movement and its rhetoric of hate and racism. However, although 4chan is increasingly “covered” by the mainstream media, we know little about how it actually operates and how instrumental it is in spreading hate on other social platforms. A new study, with colleagues at UCL, Telefonica, and University of Rome now sheds light on 4chan and in particular, on /pol/, the “politically incorrect” board.

What is 4chan anyway?

4chan is an imageboard site, built around a typical bulletin-board model. An “original poster” creates a new thread by making a post, with one single image attached, to a board with a particular focus of interest. Other users can reply, with or without images. Some of 4chan’s most important aspects are anonymity (there is no identity associated with posts) and ephemerality (inactive threads are routinely deleted).

4chan currently features 69 boards, split into 7 high level categories, e.g. Japanese Culture or Adult. In our study, we focused on the /pol/ board, whose declared intended purpose is “discussion of news, world events, political issues, and other related topics”. Arguably, there are two main characteristics of /pol/ threads. One is its racist connotation, with the not-so-unusual aggressive tone, offensive and derogatory language, and links to the “alt-right” movement—a segment of right-wing ideologies supporting Donald Trump and rejecting mainstream conservatism as well as immigration, multiculturalism, and political correctness. The other characteristic is the fact that it generates a substantial amount of original content and “online” culture, ranging from  the “lolcats” memes to “pepe the frog.”

This figure below shows four examples of typical /pol/ threads:

/pol/ example threads
Examples of typical /pol/ threads. Thread (A) illustrates the derogatory use of “cuck” in response to a Bernie Sanders image, (B) a casual call for genocide with an image of a woman’s cleavage and a “humorous” response, (C) /pol/’s fears that a withdrawal of Hillary Clinton would guarantee Donald Trump’s loss, and (D) shows Kek the “god” of memes via which /pol/ believes influences reality.

Raids towards other services

Another aspect of /pol/ is its reputation for coordinating and organizing so-called “raids” on other social media platforms. Raids are somewhat similar to Distributed Denial of Service (DDoS) attacks, except that rather than aiming to interrupt the service at a network level, they attempt to disrupt the community by actively harassing users and/or taking over the conversation.

Continue reading A Longitudinal Measurement Study of 4chan’s Politically Incorrect Forum and its Effect on the Web