Domain names ending in “.US” — the top-level domain for the United States — are among the most prevalent in phishing scams, new research shows. This is noteworthy because .US is overseen by the U.S. government, which is frequently the target of phishing domains ending in .US. Also, .US domains are only supposed to be available to U.S. citizens and to those who can demonstrate that they have a physical presence in the United States.
.US is the “country code top-level domain” or ccTLD of the United States. Most countries have their own ccTLDs: .MX for Mexico, for example, or .CA for Canada. But few other major countries in the world have anywhere near as many phishing domains each year as .US.
That’s according to The Interisle Consulting Group, which gathers phishing data from multiple industry sources and publishes an annual report on the latest trends. Interisle’s newest study examined six million phishing reports between May 1, 2022 and April 30, 2023, and found 30,000 .US phishing domains.
.US is overseen by the National Telecommunications and Information Administration (NTIA), an executive branch agency of the U.S. Department of Commerce. However, NTIA currently contracts out the management of the .US domain to GoDaddy, by far the world’s largest domain registrar.
Under NTIA regulations, the administrator of the .US registry must take certain steps to verify that their customers actually reside in the United States, or own organizations based in the U.S. But Interisle found that whatever GoDaddy was doing to manage that vetting process wasn’t working.
“The .US ‘nexus’ requirement theoretically limits registrations to parties with a national connection, but .US had very high numbers of phishing domains,” Interisle wrote. “This indicates a possible problem with the administration or application of the nexus requirements.”
Dean Marks is emeritus executive director for a group called the Coalition for Online Accountability, which has been critical of the NTIA’s stewardship of .US. Marks says virtually all European Union member state ccTLDs that enforce nexus restrictions also have massively lower levels of abuse due to their policies and oversight.
“Even very large ccTLDs, like .de for Germany — which has a far larger market share of domain name registrations than .US — have very low levels of abuse, including phishing and malware,” Marks told KrebsOnSecurity. “In my view, this situation with .US should not be acceptable to the U.S. government overall, nor to the US public.”
Marks said there are very few phishing domains ever registered in other ccTLDs that also restrict registrations to their citizens, such as .HU (Hungary), .NZ (New Zealand), and .FI (Finland), where a connection to the country, a proof of identity, or evidence of incorporation are required.
“Or .LK (Sri Lanka), where the acceptable use policy includes a ‘lock and suspend’ if domains are reported for suspicious activity,” Marks said. “These ccTLDs make a strong case for validating domain registrants in the interest of public safety.”
Sadly, .US has been a cesspool of phishing activity for many years. As far back as 2018, Interisle found .US domains were the worst in the world for spam, botnet (attack infrastructure for DDOS etc.) and illicit or harmful content. Back then, .US was being operated by a different contractor.
In response to questions from KrebsOnSecurity, GoDaddy said all .US registrants must certify that they meet the NTIA’s nexus requirements. But this appears to be little more than an affirmative response that is already pre-selected for all new registrants.
Attempting to register a .US domain through GoDaddy, for example, leads to a U.S. Registration Information page that auto-populates the nexus attestation field with the response, “I am a citizen of the US.” Other options include, “I am a permanent resident of the US,” and “My primary domicile is in the US.” It currently costs just $4.99 to obtain a .US domain through GoDaddy.
GoDaddy said it also conducts a scan of selected registration request information, and conducts “spot checks” on registrant information.
“We conduct regular reviews, per policy, of registration data within the Registry database to determine Nexus compliance with ongoing communications to registrars and registrants,” the company said in a written statement.
GoDaddy says it “is committed to supporting a safer online environment and proactively addressing this issue by assessing it against our own anti-abuse mitigation system.”
“We stand against DNS abuse in any form and maintain multiple systems and protocols to protect all the TLDs we operate,” the statement continued. “We will continue to work with registrars, cybersecurity firms and other stakeholders to make progress with this complex challenge.”
Interisle found significant numbers of .US domains were registered to attack some of the United States’ most prominent companies, including Bank of America, Amazon, Apple, AT&T, Citi, Comcast, Microsoft, Meta, and Target.
“Ironically, at least 109 of the .US domains in our data were used to attack the United States government, specifically the United States Postal Service and its customers,” Interisle wrote. “.US domains were also used to attack foreign government operations: six .US domains were used to attack Australian government services, six attacked Great’s Britain’s Royal Mail, one attacked Canada Post, and one attacked the Denmark Tax Authority.”
The NTIA recently published a proposal that would allow GoDaddy to redact registrant data from WHOIS registration records. The current charter for .US specifies that all .US registration records be public.
Interisle argues that without more stringent efforts to verify a United States nexus for new .US domain registrants, the NTIA’s proposal will make it even more difficult to identify phishers and verify registrants’ identities and nexus qualifications.
In a written statement, the NTIA said DNS abuse is a priority issue for the agency, and that NTIA supports “evidence-based policymaking.”
“We look forward to reviewing the report and will engage with our contractor for the .US domain on steps that we can take not only to address phishing, but the other forms of DNS abuse as well,” the statement reads.
Interisle sources its phishing data from several places, including the Anti-Phishing Working Group (APWG), OpenPhish, PhishTank, and Spamhaus. For more phishing facts, see Interisle’s 2023 Phishing Landscape report (PDF).’
Update, Sept. 5, 1:44 p.m. ET: Updated story with statement provided today by the NTIA.
Security consulting giant Kroll disclosed today that a SIM-swapping attack against one of its employees led to the theft of user information for multiple cryptocurrency platforms that are relying on Kroll services in their ongoing bankruptcy proceedings. And there are indications that fraudsters may already be exploiting the stolen data in phishing attacks.
Cryptocurrency lender BlockFi and the now-collapsed crypto trading platform FTX each disclosed data breaches this week thanks to a recent SIM-swapping attack targeting an employee of Kroll — the company handling both firms’ bankruptcy restructuring.
In a statement released today, New York City-based Kroll said it was informed that on Aug. 19, 2023, someone targeted a T-Mobile phone number belonging to a Kroll employee “in a highly sophisticated ‘SIM swapping’ attack.”
“Specifically, T-Mobile, without any authority from or contact with Kroll or its employees, transferred that employee’s phone number to the threat actor’s phone at their request,” the statement continues. “As a result, it appears the threat actor gained access to certain files containing personal information of bankruptcy claimants in the matters of BlockFi, FTX and Genesis.”
T-Mobile has not yet responded to requests for comment.
Countless websites and online services use SMS text messages for both password resets and multi-factor authentication. This means that stealing someone’s phone number often can let cybercriminals hijack the target’s entire digital life in short order — including access to any financial, email and social media accounts tied to that phone number.
SIM-swapping groups will often call employees on their mobile devices, pretend to be someone from the company’s IT department, and then try to get the employee to visit a phishing website that mimics the company’s login page.
Multiple SIM-swapping gangs have had great success using this method to target T-Mobile employees for the purposes of reselling a cybercrime service that can be hired to divert any T-Mobile user’s text messages and phone calls to another device.
In February 2023, KrebsOnSecurity chronicled SIM-swapping attacks claimed by these groups against T-Mobile employees in more than 100 separate incidents in the second half of 2022. The average cost to SIM swap any T-Mobile phone number was approximately $1,500.
The unfortunate result of the SIM-swap against the Kroll employee is that people who had financial ties to BlockFi, FTX, or Genesis now face increased risk of becoming targets of SIM-swapping and phishing attacks themselves.
And there is some indication this is already happening. Multiple readers who said they got breach notices from Kroll today also shared phishing emails they received this morning that spoofed FTX and claimed, “You have been identified as an eligible client to begin withdrawing digital assets from your FTX account.”
A phishing message targeting FTX users that went out en masse today.
A major portion of Kroll’s business comes from helping organizations manage cyber risk. Kroll is often called in to investigate data breaches, and it also sells identity protection services to companies that recently experienced a breach and are grasping at ways to demonstrate that they doing something to protect their customers from further harm.
Kroll did not respond to questions. But it’s a good bet that BlockFi, FTX and Genesis customers will soon enjoy yet another offering of free credit monitoring as a result of the T-Mobile SIM swap.
Kroll’s website says it employs “elite cyber risk leaders uniquely positioned to deliver end-to-end cyber security services worldwide.” Apparently, these elite cyber risk leaders did not consider the increased attack surface presented by their employees using T-Mobile for wireless service.
The SIM-swapping attack against Kroll is a timely reminder that you should do whatever you can to minimize your reliance on mobile phone companies for your security. For example, many online services require you to provide a phone number upon registering an account, but that number can often be removed from your profile afterwards.
Why do I suggest this? Many online services allow users to reset their passwords just by clicking a link sent via SMS, and this unfortunately widespread practice has turned mobile phone numbers into de facto identity documents. Which means losing control over your phone number thanks to an unauthorized SIM swap or mobile number port-out, divorce, job termination or financial crisis can be devastating.
If you haven’t done so lately, take a moment to inventory your most important online accounts, and see how many of them can still have their password reset by receiving an SMS at the phone number on file. This may require stepping through the website’s account recovery or lost password flow.
If the account that stores your mobile phone number does not allow you to delete your number, check to see whether there is an option to disallow SMS or phone calls for authentication and account recovery. If more secure options are available, such as a security key or a one-time code from a mobile authentication app, please take advantage of those instead. The website 2fa.directory is a good starting point for this analysis.
Now, you might think that the mobile providers would share some culpability when a customer suffers a financial loss because a mobile store employee got tricked into transferring that customer’s phone number to criminals. But earlier this year, a California judge dismissed a lawsuit against AT&T that stemmed from a 2017 SIM-swapping attack which netted the thieves more than $24 million in cryptocurrency.
In large metropolitan areas, tourists are often easy to spot because they’re far more inclined than locals to gaze upward at the surrounding skyscrapers. Security experts say this same tourist dynamic is a dead giveaway in virtually all computer intrusions that lead to devastating attacks like data theft and ransomware, and that more organizations should set simple virtual tripwires that sound the alarm when authorized users and devices are spotted exhibiting this behavior.
In a blog post published last month, Cisco Talos said it was seeing a worrisome “increase in the rate of high-sophistication attacks on network infrastructure.” Cisco’s warning comes amid a flurry of successful data ransom and state-sponsored cyber espionage attacks targeting some of the most well-defended networks on the planet.
But despite their increasing complexity, a great many initial intrusions that lead to data theft could be nipped in the bud if more organizations started looking for the telltale signs of newly-arrived cybercriminals behaving like network tourists, Cisco says.
“One of the most important things to talk about here is that in each of the cases we’ve seen, the threat actors are taking the type of ‘first steps’ that someone who wants to understand (and control) your environment would take,” Cisco’s Hazel Burton wrote. “Examples we have observed include threat actors performing a ‘show config,’ ‘show interface,’ ‘show route,’ ‘show arp table’ and a ‘show CDP neighbor.’ All these actions give the attackers a picture of a router’s perspective of the network, and an understanding of what foothold they have.”
Cisco’s alert concerned espionage attacks from China and Russia that abused vulnerabilities in aging, end-of-life network routers. But at a very important level, it doesn’t matter how or why the attackers got that initial foothold on your network.
It might be zero-day vulnerabilities in your network firewall or file-transfer appliance. Your more immediate and primary concern has to be: How quickly can you detect and detach that initial foothold?
The same tourist behavior that Cisco described attackers exhibiting vis-a-vis older routers is also incredibly common early on in ransomware and data ransom attacks — which often unfurl in secret over days or weeks as attackers methodically identify and compromise a victim’s key network assets.
These virtual hostage situations usually begin with the intruders purchasing access to the target’s network from dark web brokers who resell access to stolen credentials and compromised computers. As a result, when those stolen resources first get used by would-be data thieves, almost invariably the attackers will run a series of basic commands asking the local system to confirm exactly who and where they are on the victim’s network.
This fundamental reality about modern cyberattacks — that cybercriminals almost always orient themselves by “looking up” who and where they are upon entering a foreign network for the first time — forms the business model of an innovative security company called Thinkst, which gives away easy-to-use tripwires or “canaries” that can fire off an alert whenever all sorts of suspicious activity is witnessed.
“Many people have pointed out that there are a handful of commands that are overwhelmingly run by attackers on compromised hosts (and seldom ever by regular users/usage),” the Thinkst website explains. “Reliably alerting when a user on your code-sign server runs whoami.exe can mean the difference between catching a compromise in week-1 (before the attackers dig in) and learning about the attack on CNN.”
These canaries — or “canary tokens” — are meant to be embedded inside regular files, acting much like a web beacon or web bug that tracks when someone opens an email.
The Canary Tokens website from Thinkst Canary lists nearly two-dozen free customizable canaries.
“Imagine doing that, but for file reads, database queries, process executions or patterns in log files,” the Canary Tokens documentation explains. “Canarytokens does all this and more, letting you implant traps in your production systems rather than setting up separate honeypots.”
Thinkst operates alongside a burgeoning industry offering so-called “deception” or “honeypot” services — those designed to confuse, disrupt and entangle network intruders. But in an interview with KrebsOnSecurity, Thinkst founder and CEO Haroon Meer said most deception techniques involve some degree of hubris.
“Meaning, you’ll have deception teams in your network playing spy versus spy with people trying to break in, and it becomes this whole counterintelligence thing,” Meer said. “Nobody really has time for that. Instead, we are saying literally the opposite: That you’ve probably got all these [security improvement] projects that are going to take forever. But while you’re doing all that, just drop these 10 canaries, because everything else is going to take a long time to do.”
The idea here is to lay traps in sensitive areas of your network or web applications where few authorized users should ever trod. Importantly, the canary tokens themselves are useless to an attacker. For example, that AWS canary token sure looks like the digital keys to your cloud, but the token itself offers no access. It’s just a lure for the bad guys, and you get an alert when and if it is ever touched.
One nice thing about canary tokens is that Thinkst gives them away for free. Head over to canarytokens.org, and choose from a drop-down menu of available tokens, including:
-a web bug / URL token, designed to alert when a particular URL is visited;
-a DNS token, which alerts when a hostname is requested;
-an AWS token, which alerts when a specific Amazon Web Services key is used;
-a “custom exe” token, to alert when a specific Windows executable file or DLL is run;
-a “sensitive command” token, to alert when a suspicious Windows command is run.
-a Microsoft Excel/Word token, which alerts when a specific Excel or Word file is accessed.
Much like a “wet paint” sign often encourages people to touch a freshly painted surface anyway, attackers often can’t help themselves when they enter a foreign network and stumble upon what appear to be key digital assets, Meer says.
“If an attacker lands on your server and finds a key to your cloud environment, it’s really hard for them not to try it once,” Meer said. “Also, when these sorts of actors do land in a network, they have to orient themselves, and while doing that they are going to trip canaries.”
Meer says canary tokens are as likely to trip up attackers as they are “red teams,” security experts hired or employed by companies seeking to continuously probe their own computer systems and networks for security weaknesses.
“The concept and use of canary tokens has made me very hesitant to use credentials gained during an engagement, versus finding alternative means to an end goal,” wrote Shubham Shah, a penetration tester and co-founder of the security firm Assetnote. “If the aim is to increase the time taken for attackers, canary tokens work well.”
Thinkst makes money by selling Canary Tools, which are honeypots that emulate full blown systems like Windows servers or IBM mainframes. They deploy in minutes and include a personalized, private Canarytoken server.
“If you’ve got a sophisticated defense team, you can start putting these things in really interesting places,” Meer said. “Everyone says their stuff is simple, but we obsess over it. It’s really got to be so simple that people can’t mess it up. And if it works, it’s the best bang for your security buck you’re going to get.”
Further reading:
Dark Reading: Credential Canaries Create Minefield for Attackers
NCC Group: Extending a Thinkst Canary to Become an Interactive Honeypot
Cruise Automation’s experience deploying canary tokens