CHAPTER 1
The One Patch Most Needed in Cybersecurity

Everything's fine today, that is our illusion.

—Voltaire, 17591

In a single year, cyberattacks resulted in one billion records compromised and financial losses of $400 billion.2 This led Forbes Magazine to declare it “The Year of the Mega Data Breach.”3,4 Soon afterward, the head of the largest insurer, Lloyd's of London—a marketplace for a collection of insurance companies, reinsurance companies, and other types of financial backers—said cybersecurity is the “biggest, most systemic risk” he has seen in his 42 years in insurance.5 The year of that article was 2014. A lot has happened since then.

By multiple measures, cybersecurity risk has been increasing every year since 2014. For example, records breached in 2021 were, according to one source, 22 times as high as 2014.6 It hasn't peaked. We will only become more dependent on—and more vulnerable to—the technologies that drive our prosperity. We can try to reduce these risks, but resources are limited. To management, these risks may seem abstract, especially if they haven't experienced these losses directly. And yet we need to convince management, in their language, that these issues require their attention and a significant budget. Once we have that, we can try to identify and address higher priority risks first.

The title of this book is self‐explanatory. We will talk about how we can measure risks in cybersecurity and why it is important to change how we currently do it. For now, we will just make the case that there is a reason to be worried—both about the threats to cybersecurity and the adequacy of methods to assess them.

Insurance: A Canary in the Coal Mine

One of the authors of this book, Richard Seiersen, was a chief information security officer (CISO) who is now working as a chief risk officer (CRO) for the cyber insurance firm Resilience. These two viewpoints provide a useful perspective on cybersecurity risk. Insurance is at its core a “put your money where your mouth is” business. When insurers make bad bets, it catches up to them. However, to be competitive they can't just charge whatever they want. They have a strong incentive to gather a lot of data, do the math, and work out what makes a good bet in the risks they cover. That doesn't mean they are always right. It is a bet, after all. But they've done their homework, and their analysis is usually better than what most firms can muster.

Richard would point out that insurance companies reveal their concerns about a risk when they increase their premiums, tighten their underwriting requirements, or quit selling a type of coverage altogether. They are a sort of canary in the coal mine of risks. What has been happening in the field of cyber insurance is a type of leading indicator CISOs should pay attention to.

According to the National Association of Insurance Commissioners (NAIC), in the years from 2017 to 2021, total premiums collected have increased by 45%, and the share of those premiums paid out for claims has more than doubled in that same period.7 This means total cyber insurance claims paid has more than tripled in that same period. Note that claims just cover some losses. They exclude the retention (what retail consumer insurance would call a deductible), anything over the limit covered by the insurer, and exclusions such as acts of war.

If claims are completely independent of each other, then there is some expected variation from year to year, just like the total from rolling 100 dice will give you a slightly different answer from rolling another 100 dice. Insurance companies plan for that in how they manage their reserves for paying claims. However, the amount of change the NAIC observed is far beyond what could be explained as a random fluke. There are common, underlying trends driving all claims to be more frequent and more costly. This is the “systemic risk” mentioned earlier by the head of Lloyd's. In addition to claims being larger and more frequent, there is a risk that many claims could all happen at the same time making it difficult or impossible for an insurer to cover them. Furthermore, certain recent developments have made systemic risks an even bigger problem for insurers.

A key legal battle created a new systemic risk for insurers, which forced them to rewrite policies or, in some cases, get out of cyber insurance. In January 2022, Chubb, the largest cyber insurance provider, lost a case over whether it should cover $1.4 billion in losses claimed by the pharmaceutical giant Merck.8 Merck was hit by malicious code known as “NotPetya,” which encrypted the data on thousands of Merck's computers.

Because the source of the attack was six Russians with ties to Russian intelligence agencies, Chubb argued that this was an act of war, which is typically excluded in property insurance. But the court ruled the policy excluded only physical warfare, not cyber war. Other insurers took notice and responded by writing much more stringent underwriting requirements. In August 2022, Lloyd's of London advised all cyber insurers selling through its platform to stop selling coverage for cyberattacks that are sponsored by government agencies.9

The NotPetya malware, which attacked Merck, was based on some previous code known as Petya. While Petya was used in ransomware, the attack on Merck did not demand ransom. This code, created by Russia to attack Ukrainian systems, was simply for the purpose of destruction. While both destructive and financially harmful for those effected, it could have been much worse.

A different hack on the company SolarWinds shows how widely one piece of malware can be spread. SolarWinds develops system performance monitoring software. One of its software packages, the Orion network management system, is used by over 30,000 public and private institutions. In 2020, it was revealed that an update for Orion, which SolarWinds sent to its customers, contained some malicious code. While the attack was widespread, it seems that companies (especially insurance) dodged a bullet. The SolarWinds hack was a major attack by any standard, but the motive appears to be access to classified government data more than exploiting individuals.

The original target of NotPetya, on the other hand, was a single Ukrainian software company but the malicious code leaked out to numerous Ukrainian entities such as the National Bank of Ukraine—and spread across the globe. It led to billions of dollars of impact—much of which was collateral damage. And still it was not as widespread as the malware that hit SolarWinds. If one attack were as widespread as SolarWinds and as destructive as NotPetya, we would have had a completely different story.

The change in act‐of‐war exclusions combined with an apparent increase in frequency of exactly that kind of event adds to a growing list of systemic risks. Potential weaknesses in widely used software; interdependent network access between companies, vendors, and clients; and the possibility of large, coordinated attacks can affect much more than even one big company. We said this in the first edition of this book in 2016, and it is just as true now if not more. If this results in multiple major claims in a short period of time, this may be a bigger burden than insurers can realistically cover. What worries the insurance companies is that even the biggest attacks seen so far aren't as big as they could have been.

The Global Attack Surface

As we mentioned above, insurance companies have the option of limiting their risk by changing policy language or simply not selling insurance to you if they feel your risk is too great. They can simply choose not to participate in that risk. You don't have that option. Whatever risks your insurers won't cover are still carried by you. Nation‐states, organized crime, hacktivist entities, and insider threats want our secrets, our money, and our intellectual property, and some want our complete demise. That's not just being dramatic. If you are reading this book, you probably already accept the gravity of the situation.

What is causing such a dramatic rise in breach and the anticipation of even more breaches? It is called “attack surface.” Attack surface is usually defined as the total of all kinds of exposures of an information system. It exposes value to untrusted sources. You don't need to be a security professional to get this. Your home, your bank account, your family, and your identity all have an attack surface. If you received identity theft protection as a federal employee, or as a customer of a major retailer, then you received that courtesy of an attack surface. These companies put the digital you within reach of criminals. Directly or indirectly, the Internet facilitated this. This evolution happened quickly and not always with the knowledge or direct permission of all interested parties like you.

Various definitions of attack surface consider the ways into and out of a system, the defenses of that system, and sometimes the value of data in that system.10,11 Some definitions refer to the attack surface of a system and some refer to the attack surface of a network, but either might be too narrow even for a given firm. We might also define an “enterprise attack surface” that not only consists of all systems and networks in that organization but also the...