Category Archives: Infoblox

Don’t Let Your Domain Name Become a “Sitting Duck”

More than a million domain names — including many registered by Fortune 100 firms and brand protection companies — are vulnerable to takeover by cybercriminals thanks to authentication weaknesses at a number of large web hosting providers and domain registrars, new research finds.

Image: Shutterstock.

Your Web browser knows how to find a site like example.com thanks to the global Domain Name System (DNS), which serves as a kind of phone book for the Internet by translating human-friendly website names (example.com) into numeric Internet addresses.

When someone registers a domain name, the registrar will typically provide two sets of DNS records that the customer then needs to assign to their domain. Those records are crucial because they allow Web browsers to find the Internet address of the hosting provider that is serving that domain.

But potential problems can arise when a domain’s DNS records are “lame,” meaning the authoritative name server does not have enough information about the domain and can’t resolve queries to find it. A domain can become lame in a variety of ways, such as when it is not assigned an Internet address, or because the name servers in the domain’s authoritative record are misconfigured or missing.

The reason lame domains are problematic is that a number of Web hosting and DNS providers allow users to claim control over a domain without accessing the true owner’s account at their DNS provider or registrar.

If this threat sounds familiar, that’s because it is hardly new. Back in 2019, KrebsOnSecurity wrote about thieves employing this method to seize control over thousands of domains registered at GoDaddy, and using those to send bomb threats and sextortion emails (GoDaddy says they fixed that weakness in their systems not long after that 2019 story).

In the 2019 campaign, the spammers created accounts on GoDaddy and were able to take over vulnerable domains simply by registering a free account at GoDaddy and being assigned the same DNS servers as the hijacked domain.

Three years before that, the same pervasive weakness was described in a blog post by security researcher Matthew Bryant, who showed how one could commandeer at least 120,000 domains via DNS weaknesses at some of the world’s largest hosting providers.

Incredibly, new research jointly released today by security experts at Infoblox and Eclypsium finds this same authentication weakness is still present at a number of large hosting and DNS providers.

“It’s easy to exploit, very hard to detect, and it’s entirely preventable,” said Dave Mitchell, principal threat researcher at Infoblox. “Free services make it easier [to exploit] at scale. And the bulk of these are at a handful of DNS providers.”

SITTING DUCKS

Infoblox’s report found there are multiple cybercriminal groups abusing these stolen domains as a globally dispersed “traffic distribution system,” which can be used to mask the true source or destination of web traffic and to funnel Web users to malicious or phishous websites.

Commandeering domains this way also can allow thieves to impersonate trusted brands and abuse their positive or at least neutral reputation when sending email from those domains, as we saw in 2019 with the GoDaddy attacks.

“Hijacked domains have been used directly in phishing attacks and scams, as well as large spam systems,” reads the Infoblox report, which refers to lame domains as “Sitting Ducks.” “There is evidence that some domains were used for Cobalt Strike and other malware command and control (C2). Other attacks have used hijacked domains in targeted phishing attacks by creating lookalike subdomains. A few actors have stockpiled hijacked domains for an unknown purpose.”

Eclypsium researchers estimate there are currently about one million Sitting Duck domains, and that at least 30,000 of them have been hijacked for malicious use since 2019.

“As of the time of writing, numerous DNS providers enable this through weak or nonexistent verification of domain ownership for a given account,” Eclypsium wrote.

The security firms said they found a number of compromised Sitting Duck domains were originally registered by brand protection companies that specialize in defensive domain registrations (reserving look-alike domains for top brands before those names can be grabbed by scammers) and combating trademark infringement.

For example, Infoblox found cybercriminal groups using a Sitting Duck domain called clickermediacorp[.]com, which was initially registered on behalf of CBS Interactive Inc. by the brand protection firm MarkMonitor.

Another hijacked Sitting Duck domain — anti-phishing[.]org — was registered in 2003 by the Anti-Phishing Working Group (APWG), a cybersecurity not-for-profit organization that closely tracks phishing attacks.

In many cases, the researchers discovered Sitting Duck domains that appear to have been configured to auto-renew at the registrar, but the authoritative DNS or hosting services were not renewed.

The researchers say Sitting Duck domains all possess three attributes that makes them vulnerable to takeover:

1) the domain uses or delegates authoritative DNS services to a different provider than the domain registrar;
2) the authoritative name server(s) for the domain does not have information about the Internet address the domain should point to;
3) the authoritative DNS provider is “exploitable,” i.e. an attacker can claim the domain at the provider and set up DNS records without access to the valid domain owner’s account at the domain registrar.

Image: Infoblox.

How does one know whether a DNS provider is exploitable? There is a frequently updated list published on GitHub called “Can I take over DNS,” which has been documenting exploitability by DNS provider over the past several years. The list includes examples for each of the named DNS providers.

In the case of the aforementioned Sitting Duck domain clickermediacorp[.]com, the domain was originally registered by MarkMonitor, but it appears to have been hijacked by scammers by claiming it at the web hosting firm DNSMadeEasy, which is owned by Digicert, one of the industry’s largest issuers of digital certificates (SSL/TLS certificates).

In an interview with KrebsOnSecurity, DNSMadeEasy founder and senior vice president Steve Job said the problem isn’t really his company’s to solve, noting that DNS providers who are also not domain registrars have no real way of validating whether a given customer legitimately owns the domain being claimed.

“We do shut down abusive accounts when we find them,” Job said. “But it’s my belief that the onus needs to be on the [domain registrants] themselves. If you’re going to buy something and point it somewhere you have no control over, we can’t prevent that.”

Infoblox, Eclypsium, and the DNS wiki listing at Github all say that web hosting giant Digital Ocean is among the vulnerable hosting firms. In response to questions, Digital Ocean said it was exploring options for mitigating such activity.

“The DigitalOcean DNS service is not authoritative, and we are not a domain registrar,” Digital Ocean wrote in an emailed response. “Where a domain owner has delegated authority to our DNS infrastructure with their registrar, and they have allowed their ownership of that DNS record in our infrastructure to lapse, that becomes a ‘lame delegation’ under this hijack model. We believe the root cause, ultimately, is poor management of domain name configuration by the owner, akin to leaving your keys in your unlocked car, but we acknowledge the opportunity to adjust our non-authoritative DNS service guardrails in an effort to help minimize the impact of a lapse in hygiene at the authoritative DNS level. We’re connected with the research teams to explore additional mitigation options.”

In a statement provided to KrebsOnSecurity, the hosting provider and registrar Hostinger said they were working to implement a solution to prevent lame duck attacks in the “upcoming weeks.”

“We are working on implementing an SOA-based domain verification system,” Hostinger wrote. “Custom nameservers with a Start of Authority (SOA) record will be used to verify whether the domain truly belongs to the customer. We aim to launch this user-friendly solution by the end of August. The final step is to deprecate preview domains, a functionality sometimes used by customers with malicious intents. Preview domains will be deprecated by the end of September. Legitimate users will be able to use randomly generated temporary subdomains instead.”

What did DNS providers that have struggled with this issue in the past do to address these authentication challenges? The security firms said that to claim a domain name, the best practice providers gave the account holder random name servers that required a change at the registrar before the domains could go live. They also found the best practice providers used various mechanisms to ensure that the newly assigned name server hosts did not match previous name server assignments.

[Side note: Infoblox observed that many of the hijacked domains were being hosted at Stark Industries Solutions, a sprawling hosting provider that appeared two weeks before Russia invaded Ukraine and has become the epicenter of countless cyberattacks against enemies of Russia].

Both Infoblox and Eclypsium said that without more cooperation and less finger-pointing by all stakeholders in the global DNS, attacks on sitting duck domains will continue to rise, with domain registrants and regular Internet users caught in the middle.

“Government organizations, regulators, and standards bodies should consider long-term solutions to vulnerabilities in the DNS management attack surface,” the Infoblox report concludes.

.US Harbors Prolific Malicious Link Shortening Service

The top-level domain for the United States — .US — is home to thousands of newly-registered domains tied to a malicious link shortening service that facilitates malware and phishing scams, new research suggests. The findings come close on the heels of a report that identified .US domains as among the most prevalent in phishing attacks over the past year.

Researchers at Infoblox say they’ve been tracking what appears to be a three-year-old link shortening service that is catering to phishers and malware purveyors. Infoblox found the domains involved are typically three to seven characters long, and hosted on bulletproof hosting providers that charge a premium to ignore any abuse or legal complaints. The short domains don’t host any content themselves, but are used to obfuscate the real address of landing pages that try to phish users or install malware.

A graphic describing the operations of a malicious link shortening service that Infoblox has dubbed “Prolific Puma.”

Infoblox says it’s unclear how the phishing and malware landing pages tied to this service are being initially promoted, although they suspect it is mainly through scams targeting people on their phones via SMS. A new report says the company mapped the contours of this link shortening service thanks in part to pseudo-random patterns in the short domains, which all appear on the surface to be a meaningless jumble of letters and numbers.

“This came to our attention because we have systems that detect registrations that use domain name generation algorithms,” said Renee Burton, head of threat intelligence at Infoblox. “We have not found any legitimate content served through their shorteners.”

Infoblox determined that until May 2023, domains ending in .info accounted for the bulk of new registrations tied to the malicious link shortening service, which Infoblox has dubbed “Prolific Puma.” Since then, they found that whoever is responsible for running the service has used .US for approximately 55 percent of the total domains created, with several dozen new malicious .US domains registered daily.

.US is overseen by the National Telecommunications and Information Administration (NTIA), an executive branch agency of the U.S. Department of Commerce. But Uncle Sam has long outsourced the management of .US to various private companies, which have gradually allowed the United States’s top-level domain to devolve into a cesspool of phishing activity.

Or so concludes The Interisle Consulting Group, which gathers phishing data from multiple industry sources and publishes an annual report on the latest trends. 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.

Interisle’s newest study examined six million phishing reports between May 1, 2022 and April 30, 2023, and identified approximately 30,000 .US phishing domains. 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. Others were used to impersonate or attack U.S. government agencies.

Under NTIA regulations, domain registrars processing .US domain registrations must take certain steps (PDF) to verify that those customers actually reside in the United States, or else own organizations based in the U.S. However, if one registers a .US domain through GoDaddy — the largest domain registrar and the current administrator of the .US contract — the way one “proves” their U.S. nexus is simply by choosing from one of three pre-selected affirmative responses.

In an age when most domain registrars are automatically redacting customer information from publicly accessible registration records to avoid running afoul of European privacy laws, .US has remained something of an outlier because its charter specifies that all registration records be made public. However, Infoblox said it found more than 2,000 malicious link shortener domains ending in .US registered since October 2023 through NameSilo that have somehow subverted the transparency requirements for the usTLD and converted to private registrations.

“Through our own experience with NameSilo, it is not possible to select private registration for domains in the usTLD through their interface,” Infoblox wrote. “And yet, it was done. Of the total domains with private records, over 99% were registered with NameSilo. At this time, we are not able to explain this behavior.”

NameSilo CEO Kristaps Ronka said the company actively responds to reports about abusive domains, but that it hasn’t seen any abuse reports related to Infoblox’s findings.

“We take down hundreds to thousands of domains, lots of them proactively to combat abuse,” Ronka said. “Our current abuse rate on abuseIQ for example is currently at 0%. AbuseIQ receives reports from countless sources and we are yet to see these ‘Puma’ abuse reports.”

Experts who track domains associated with malware and phishing say even phony information supplied at registration is useful in identifying potentially malicious or phishous domains before they can be used for abuse.

For example, when it was registered through NameSilo in July 2023, the domain 1ox[.]us — like thousands of others — listed its registrant as “Leila Puma” at a street address in Poland, and the email address blackpumaoct33@ukr.net. But according to DomainTools.com, on Oct. 1, 2023 those records were redacted and hidden by NameSilo.

Infoblox notes that the username portion of the email address appears to be a reference to the song October 33 by the Black Pumas, an Austin, Texas based psychedelic soul band. The Black Pumas aren’t exactly a household name, but they did recently have a popular Youtube video that featured a cover of the Kinks song “Strangers,” which included an emotional visual narrative about Ukrainians seeking refuge from the Russian invasion, titled “Ukraine Strangers.” Also, Leila Puma’s email address is at a Ukrainian email provider.

DomainTools shows that hundreds of other malicious domains tied to Prolific Puma previously were registered through NameCheap to a “Josef Bakhovsky” at a different street address in Poland. According to ancestry.com, the anglicized version of this surname — Bakovski — is the traditional name for someone from Bakowce, which is now known as Bakivtsi and is in Ukraine.

This possible Polish and/or Ukrainian connection may or may not tell us something about the “who” behind this link shortening service, but those details are useful for identifying and grouping these malicious short domains. However, even this meager visibility into .US registration data is now under threat.

The NTIA recently published a proposal that would allow registrars to redact all registrant data from WHOIS registration records for .US domains. A broad array of industry groups have filed comments opposing the proposed changes, saying they threaten to remove the last vestiges of accountability for a top-level domain that is already overrun with cybercrime activity.

Infoblox’s Burton says Prolific Puma is remarkable because they’ve been able to facilitate malicious activities for years while going largely unnoticed by the security industry.

“This exposes how persistent the criminal economy can be at a supply chain level,” Burton said. “We’re always looking at the end malware or phishing page, but what we’re finding here is that there’s this middle layer of DNS threat actors persisting for years without notice.”

Infoblox’s full report on Prolific Puma is here.