In my blog, Password Constraints and Their Unintended Security Consequences, I advocate for the use of passphrases. Embedded in the comments section, one of our readers Ben makes a very astute observation:

What happens when attackers start guessing by the word instead of by the letter? Then a four-word passphrase effectively becomes a four-character password.

What Ben is describing is called a “passphrase token attack,” and it’s real. With a good passphrase, the attack is not much of a threat though. First, a definition, then I’ll explain why.

What’s a token?

In the context of a passphrase token attack, a token is a grouping of letters, AKA a word. The passphrase made famous by the comic xkcd, “correct horse battery staple,” is 28 characters long. But, in a passphrase token attack, I wouldn’t try to guess all possible combinations of 28 letters. I would guess combinations of entire words, or tokens, each representing a group of characters.

The math behind passphrases

One might assume, as Ben did, that a four-word password is the same as a four-character password. But that’s a math error. Specifically, 95≠1,000,000. 

Here’s why: There are 95 letters, numbers, and symbols that can be used for each character in a password. However, there are over a million words in the English language. For simplicity’s sake, let’s call it an even million words. If I’m thinking of a single character, then at most you have to try 95 characters to guess it. But if I ask you to guess which word I am thinking of, then you may need to guess a million words before you have guessed the word that I am thinking of. 

So while there are 95^4 possible combinations of characters for a four-character password, there are over 1,000,000^4 combinations of words for a four-word password. 

You might be thinking “But nobody knows a million words,” and you are correct. According to some research, the average person uses no more than 10,000. So, as an attacker, I’d try combinations of only the most common words. Actually, I may be able to get by with a dictionary as small as 5,000 words. But 5,000^4 is still a whole lot more combinations than 95^4.

Here is one list of 5,000 of the most commonly used words in the English language, and another of the 10,000 most commonly used words. Choosing an uncommon word is great, but even words in the top 5,000 are still far better than a complex nine-character password.

Why and how to use a passphrase

There are two major strengths of passphrases: 

1. Passphrases allow for longer, more secure passwords. It’s length that makes a passphrase a killer password. A password/passphrase that’s 20 lowercase characters long is stronger than a 14 character password that uses uppercase letters, lowercase letters, numbers, and symbols. 
2. Passphrases can be easy to remember, making creating and using passwords a lot less painful. “Aardvarks eat at the diner” is easy to remember and, at 26 characters long and including uppercase and lowercase letters, is more than 9 trillion times stronger than the password “eR$48tx!53&(oPZe”, or any other complex, 16-character password, and potentially uncrackable.

Why potentially uncrackable? Because “aardvark” is not one of the 10,000 most frequently used words and, if a word is not in the attacker’s dictionary, then you win. This is why it helps to use foreign-language words. Even common foreign words require an attacker to increase the size of their dictionary, the very factor that makes passphrase token attacks impractical. Learning a word in an obscure foreign language can be fun and pretty much assures a passphrase won’t be cracked.

As we’ve seen, cracking a passphrase can be far more difficult than cracking a password, unless you make one of two common mistakes. The first is choosing a combination of words without enough characters. “I am a cat,” for example. Although it’s four words, it’s only 10 characters long and an attacker can use a conventional brute force attack, even for a passphrase. Spaces between words can be used to increase the length and complexity of passphrases.

The second most common mistake is using a common phrase as a passphrase. I can create a dictionary of the top 1,000,000 common phrases and, if you’re using one, then it only takes at most 1,000,000 guesses to crack (about the same as a complex three-character password). 

So create your own unique passphrases and you’re all set. Most experts recommend passphrases be at least 20 characters long. But if you only go from eight characters to 16 upper and lower case letters, you’ll already be 430 trillion times better off. And if you’re creating a passphrase for a site requiring a number or symbol, it’s fine to add the same number and symbol to the end of your phrase, provided the passphrase is long to begin with.

As a side note, according to math, a five word passphrase is generally stronger than a four word passphrase, but don’t get too hung up on that.

So Ben, you are 100% right about the reality of passphrase token attacks. But, with a strong passphrase, the math says it doesn’t matter. Note: If this stuff fascinates you, or you suffer from insomnia, you might enjoy “Linguistic Cracking of Passphrases using Markov Chains.” You can download the PDF or watch this riveting thriller on YouTube. Sweet dreams.

This is the second of a three-part report on the state of three malware categories: miners, ransomware, and information stealers. 

As noted in the last blog, mining malware is on a decline, partly due to turmoil affecting cryptocurrencies. Ransomware is also on a decline (albeit a slower one). These dips are at least partly the result of the current criminal focus on information theft.

Banking Trojans, hacks, leaks, and data-dealing are huge criminal enterprises. In addition to suffering a breach, companies might now be contravening regulations like GDPR if they didn’t take the proper precautions to secure their data. The ways in which stolen data is being used is seeing constant innovation. 

Motivations for data theft

Currency

The most obvious way to profit from data theft is by stealing data directly related to money. Examples of malware that accomplishes this could include:

• Banking Trojans. These steal online banking credentials, cryptocurrency private keys, credit card details, etc. Originally for bank theft specialists, this malware group now encompasses all manner of data theft. Current examples include Trickbot, Ursnif, Dridex.
• Point of Sale (POS). These attacks scrape or skim card information from sales terminals and devices.
• Information stealing malware for hijacking other valuables including Steam keys, microtransactional or in-game items

Trade

Data that isn’t instantly lucrative to a thief can be fenced on the dark web and elsewhere. Medical records can be worth ten times more than credit cards on dark web marketplaces. A credit card can be cancelled and changed, but that’s not so easy with identity. Examples of currently traded information include:

• Credit cards. When cards are skimmed or stolen, they’re usually taken by the thousands. It’s easier to sell these on at a reduced cost and leave the actual fraud to other crooks.
• Personal information. It can be used for identity theft or extortion, including credentials, children’s data, social security information, passport details, medical records that can be used to order drugs and for identity theft, and sensitive government (or police) data

Espionage

Classified trade, research, military, and political information are constant targets of hacks and malware, for obvious reasons. The criminal, political, and intelligence worlds sometimes collide in clandestine ways in cybercrime. 

As a means of attack

While gold and gemstones are worth money, the codes to a safe or blueprints to a jewellery store are also worth a lot, despite not having much intrinsic value. Similarly, malware can be used to case an organisation and identify weaknesses in its security setup. This is usually the first step in an attack, before the real damage is done by malware or other means. 

“In late 2013, an A.T.M. in Kiev started dispensing cash at seemingly random times of day. No one had put in a card or touched a button. Cameras showed that the piles of money had been swept up by customers who appeared lucky to be there at the right moment.” –From a story that appeared in the New York Times

Just another day in the Cobalt/Carbanak Heists 

Some examples of “reconnaissance” malware include:

• Carbanak. This was the spear-tip of an attack in an infamous campaign that stole over €1 billion ($1.24 billion) from European banks, particularly in Eastern Europe. The Trojan was emailed to hundreds of bank employees. Once executed, it used keylogging and data theft to learn passwords, personnel details, and bank procedures before the main attacks were carried out, often using remote access tools. ATMs were hacked to spill out cash to waiting gang members and money was transferred to fraudulent accounts.
• Mimikatz, PsExec, and other tools. These tools are freely available and can help admins with legitimate issues like missing product keys or passwords. They can also indicate that a hacker has been on your network snooping. These software capabilities can be baked into other malware.
• Emotet. Probably the most successful botnet malware campaign of the last few years, this modular Trojan steals information to help it spread before dropping other malware. It usually arrives by phishing email before spreading like wildfire through an organisation with stolen/brute-forced credentials and exploits. Once it has delivered its payload (often banking Trojans), it uses stolen email credentials to mail itself to another victim. It’s been exfiltrating the actual contents of millions of emails for unknown purposes, and has been dropping Trickbot recently, but the crew behind the campaign can change the payload depending what’s most profitable. 

“Emotet is an advanced, modular banking Trojan that primarily functions as a downloader or dropper of other banking Trojans. Emotet continues to be among the most costly and destructive malware affecting state, local, tribal, and territorial (SLTT) governments, and the private and public sectors.”- An August 2018 warning from the American DHS

• Trickbot/Ryuk. Trickbot is a banking Trojan capable of stealing a huge array of data. In addition to banking details and cryptocurrency, it also steals data that enables other attacks, including detailed information about infected devices and networks, saved online account passwords, cookies, and web histories, and login credentials. Trickbot has been seen dropping ransomware like Bitpaymer onto machines, but recently its stolen data is used to test a company’s worth before allowing attackers to deploy remote access tools and Ryuk (ransomware) to encrypt the most valuable information they have. The people behind this Trickbot/Ryuk campaign are only going after big lucrative targets that they know they can cripple.

What are the current trends?

Emotet is hammering the business world and, according to our data, has surged in the last six months of 2018:

Data recorded between 1 July and December 31, 2018. Webroot SecureAnywhere client data.

Detection of related malware surged alongside these detections. Almost 20% of Webroot support cases since the start of December have been related to this “family” of infections (Emotet, Dridex, Ursnif, Trickbot, Ryuk, Icedid).

What can I do?

• Update everything! The success of infections such as WannaMine proved that updates to many operating systems still lag years behind. Emotet abuses similar SMB exploits to WannMine, which updates can eliminate.
• Make sure all users, and especially admins, adhere to proper password practices.
• Disable autoruns and admin shares, and limit privileges where possible.
• Don’t keep sensitive information in plain text.

What can Webroot do?

• Webroot SecureAnywherehome security products detect and remove information stealers including Emotet, Trickbot, Ursnif, Heodo, and Mimikatz, as well as any other resultant malware.
• Our Identity and Privacy Shield stops keylogging and clipboard theft, even if malware isn’t detected.
• Ongoing cybersecurity education and trainingfor end users is a must for businesses to stay secure. Remember: phishing and email tend to be the top delivery methods for this malware. 
• As well as helping you clean machines, Webroot’s support (in the case of infections such as Emotet) will help you plug security holes. Our specialised security hardening tools can be deployed through our console to all endpoints in a few clicks.

Information theft can be a very complicated business, but to tackle it, the basics have to be done. Criminals will always go for the low hanging fruit, so lifting your organisation’s data out of this category should be your first priority.But proper device protection and knowledge of good cyber hygiene are also essential to protecting your data. Stay tuned to the Webroot blog for the latest information on the newest threats.

It’ll cost you a buck. Just like everyone else’s. The use of a Social Security Number (SSN) as unique identifiers has long been a contentious subject. SSNs were never intended to be used for identification, and their ubiquitous abuse for identification and authentication has lead me to call them “Social Insecurity Numbers,” or SINs.

There was a time when my response to a breach that leaked SSNs was “the horror, the horror.” Now my cynical reaction is “big deal, they stole my public information… again.” Yes, I know it’s improper for a security expert to feel this way, but an improper response is sometimes still the correct response. 

Let me walk you through both sides of the issue: the horror and the dispassion.

The Horror

When aliens visit our lifeless planet in 2525, they will run DNA tests on our remains and they will catalog or index us by our SINs. That’s one of the things that makes the theft of SSNs worrisome. SSNs do not expire. A person may expire, their SSN does not. Social security numbers are not reused. They just stop being used. Funds may be paid to surviving spouses and children, but after that the SSNs are a permanent entry in a database.

Let’s put this into perspective. Of all of the credit cards issued between 1946 and 2012, virtually none are valid. Of all of the compromised credit cards issued between 2012 and 2018, very few remain valid. Sometimes the cards are replaced before they’re fraudulently used, and other times fraudulent use results in the cancellation of the cards. In either case, the cards are simply replaced with new account numbers. 

Compare this to SSNs. Of all of the SSNs issued since 1934, well… Have you ever see an expiration date on a Social Security card? You can change your credit card number. You can change bank. You can change your career, your doctor, your vet, your clothes, or your mind. But unless you enter the United States Federal Witness Protection Program, your SSN isn’t changing. (Actually, that’s a bit overstated. Under certain circumstances you can get a new SSN, but your SSN simply being compromised does not qualify you to change SSNs.)

According to a study published by Javelin, more social security numbers were involved in breaches in 2017 than credit cards. Think about that for a moment. Do you know anyone who has had a fraudulent purchase made on their credit card? Here’s where the problem becomes insidious. Credit card fraud is loud. You can hear it coming. I have alerts set up on my bank accounts so that I know each time a charge is made. I am alerted through text and email. One fraudulent charge and I know. I can act. 

But SSNs are quiet. Multiple applications for credit cards can be made simultaneously, but you’re not likely to find out very quickly. Pair this with a compromised email account, and you could be in big trouble. For me, it’s of serious concern.

The Dispassion

Why don’t I worry about my SSN being leaked? Because it’s already been leaked multiple times in multiple breaches. 

How do I know that? 

I don’t, I just assume it has been. Why? Because my SSN has been vulnerable to theft for decades, and there are so many compromised SSNs stocking the dark web that they’re a cheap commodity. You might even expect to encounter a “buy five credit card numbers get two SSNs free” deal, or to see them sold by the dozen, like Kleenex at Costo.  

According to Brian Stack, the Vice President of Dark Web Intelligence at Experian, Social Security numbers sell for only $1 on the dark web. In the massive Marriot breach, it wasn’t my SSN I was worried about, it was my loyalty program information. My loyalty program information is worth 20 times more than my SSN on the dark web. Loyalty program points can be used to buy travel or merchandise in airline shopping malls.

For several years, “assume the breach” has been the mindset of many security professionals, meaning that we should assume a company will be breached, or already has been breached, and we should be clear-eyed about it. It is a call to action. Put mitigations and remediation processes in place. Have an action plan. 

For the public, and I cannot emphasize this enough, this means you should assume it was your data that was compromised in the breach, and put a remediation plan in place. If the businesses holding your data assumes your data is toast, then you should too.

What You Can Do

So, if we’re adopting the fatalist position on SSN theft, but still want to protect ourselves, what’s a person to do?

• Credit freezes and fraud alerts. Both are good proactive defenses. The Federal Trade Commission (FTC) is a good place to start if you don’t know how. For information about credit freezes, check here. For information about fraud alerts and extended fraud alerts, take a look here and here.
• Use two-factor authentication. Gmail, Facebook, Twitter, and other sites offer two-factor authentication. Typically, this means you’ll need to respond to a text or email in order to log into your account. This makes it harder for the bad guys to hijack it. Not impossible, but significantly more difficult.
• Take advantage of alerts offered by financial institutions. If someone tries to log into my bank account or make a charge on my credit or debit card, I will know it immediately. 
• Be Prepared for Identity Theft. Once again, the FTC consumer information page on identity theft is a great resource for consumers, security evangelists, and businesses alike on how to build a strong defensive posture.

Identity theft is real, it can be devastating, and you need to be prepared for it. But reports of breaches that include SSNs tell me what I already know; my SSN is in the hands of cybercriminals. It has been for years.

So no, I’m not going to tell you my SSN. You’ll have to pay your dollar for it, just like everyone else.

This is the first of a three-part report on the state of three malware categories: miners, ransomware and information stealers.

In Webroot’s 2018 mid-term threat report, we outlined how cryptomining, and particularly cryptojacking, had become popular criminal tactics over the first six months of last year. This relatively novel method of cybercrime gained favour for being less resource-intensive and overtly criminal when compared to tactics involving ransomware. But mining cases and instances of mining malware seem to have dropped off significantly in the six months since this report, both anecdotally and in terms of calls to our support queue. 

The crytpo world has gone through significant turmoil in this time, so it’s possible the reduced use of malicious cryptojacking scripts is the result of tanking cryptocurrency values. It’s also possible users are benefitting from heightened awareness of the threat and taking measures to prevent their use, such as browser extensions purpose-built to stop these scripts from running. 

Setting aside the question of why for a moment, let’s take a look at some stats illustrating that decline during that time period.

Cryptojacking URLs seen by Webroot over six months beginning 1 July through 31 December, 2018, Webroot SecureAnywhere client data. 

New miner malware seen by Webroot 

Data from six months beginning 12 July through 9 Jan, 2019, Webroot data, units logarithmic.

Monero mining profitability ($)

Data covering six months from 12 July – 9 Jan, 2019, Bit Info Charts, units logarithmic

Monero price ($)

Data covering six months from 12 July through 9 Jan, 2019, World Coin Index

Interpreting the data

None of the graphs are identical, but without too much statistical comparison, I think a broad trend can be seen: malicious mining is on the decline alongside a general decline in coin value and coin mining profitability. 

Profitability affecting criminal tactics is of course not surprising. The flexibility of exploit kits and modern malware campaigns like Emotet mean that cybercriminals can change tactics and payloads quickly when they feel their malware isn’t netting as much as it should.

Thanks to the dark web, criminal code has never been easier to buy or rent than in recent years, and cryptocurrencies themselves make it easy to swap infection tactics while keeping the cash flowing. Buying or renting malicious code and malware delivery services online is easy, so the next time the threat landscape changes, expect criminals to quickly change with it. 

Should I still care about miners?

Yes, absolutely. 

Cryptocurrency, cryptomining, and malicious cryptomining aren’t disappearing. Even with this dip, 2018 was definitely a year of overall cryptocrime growth. Our advanced malware removals teams often spot miner malware on machines infected by other malware, and it can be an indication of security holes in need of patching. And any illegal mining is still capable of constantly driving up power bills and frustrating users.

Where are cybercriminals focused now?

Information theftis the current criminal undertaking of choice, a scary development with potentially long-lasting consequences for its victims that are sometimes unpredictable even to thieves. The theft, trade, and use for extortion of personal data will be the focus of our next report.

What can I do?

Cryptojacking may only be on the decline because defences against them have improved. To up your chances of turning aside this particular threat, consider doing the following:

• Update everything. Even routers can be affected by cryptojacking, so patch/update everything you can.
• Is your browser using up lots of processor? Even after a reset/reinstall? This could be a sign of cryptojacking.
• Are you seeing weird spikes in your processor? You may want to scan for miner infections.
• Don’t ignore repeated miner detections. Get onto your antivirus’ support team for assistance. This could be only the tip of the iceberg.
• Secure your RDP.

What can Webroot do?

Webroot SecureAnywhere®antivirus products detect and remove miner infections, and the web threat shield blocks malicious cryptojacking sites from springing their code on home office users. For businesses, however, the single best way to stop cryptojacking, is with DNS-level protection. DNS is particularly good at blocking cryptojacking services, no matter how many sites they try to hide behind.

Persistent mining detections might point to other security issues, such as out-of-date software or advanced persistence methods, that will need extra work to fix. Webroot’s support is quick and easy to reach.

In the end, cryptomining and cryptojacking aren’t making the same stir in the cybersecurity community they were some months ago. But they’ve far from disappeared. More users than ever are aware of the threat they pose, and developers are reacting. Fluctuations in cryptocurrency value have perhaps aided the decline, but as long as these currencies have any value cryprojackers will be worth the limited effort they require from criminals.

Watch for the use of cryptominers to be closely related to the value of various cryptocurrencies and remain on the lookout for suspicious or inexplicable CPU usage, as these may be signs that you’re being targeted by these threats. 

And of course, stay tuned to the Webroot blog for information on the latest threat trends.