Most accomplished cybercriminals go out of their way to separate their real names from their hacker handles. But among certain old-school Russian hackers it is not uncommon to find major players who have done little to prevent people from figuring out who they are in real life. A case study in this phenomenon is “x999xx,” the nickname chosen by a venerated Russian hacker who specializes in providing the initial network access to various ransomware groups.
x999xx is a well-known “access broker” who frequently sells access to hacked corporate networks — usually in the form of remote access credentials — as well as compromised databases containing large amounts of personal and financial data.
In an analysis published in February 2019, cyber intelligence firm Flashpoint called x999xx one of the most senior and prolific members of the top-tier Russian-language cybercrime forum Exploit, where x999xx could be seen frequently advertising the sale of stolen databases and network credentials.
In August 2023, x999xx sold access to a company that develops software for the real estate industry. In July 2023, x999xx advertised the sale of Social Security numbers, names, and birthdays for the citizenry of an entire U.S. state (unnamed in the auction).
A month earlier, x999xx posted a sales thread for 80 databases taken from Australia’s largest retail company. “You may use this data to demand a ransom or do something different with it,” x999xx wrote on Exploit. “Unfortunately, the flaw was patched fast. [+] no one has used the data yet [+] the data hasn’t been used to send spam [+] the data is waiting for its time.”
In October 2022, x999xx sold administrative access to a U.S. healthcare provider.
The oldest account by the name x999xx appeared in 2009 on the Russian language cybercrime forum Verified, under the email address maxnm@ozersk.com. Ozersk is a city in the Chelyabinsk region of west-central Russia.
According to the breach tracking service Constella Intelligence, the address maxnm@ozersk.com was used more than a decade ago to create an account at Vktontakte (the Russian answer to Facebook) under the name Maxim Kirtsov from Ozersk. Mr. Kirtsov’s profile — “maxnm” — says his birthday is September 5, 1991.
Personal photos Maxnm shared on Vktontakte in 2016. The caption has been machine translated from Russian.
The user x999xx registered on the Russian language cybercrime community Zloy in 2014 using the email address maxnmalias-1@yahoo.com. Constella says this email address was used in 2022 at the Russian shipping service cdek.ru by a Maksim Georgievich Kirtsov from Ozersk.
Additional searches on these contact details reveal that prior to 2009, x999xx favored the handle Maxnm on Russian cybercrime forums. Cyber intelligence company Intel 471 finds the user Maxnm registered on Zloy in 2006 from an Internet address in Chelyabinsk, using the email address kirtsov@telecom.ozersk.ru.
That same email address was used to create Maxnm accounts on several other crime forums, including Spamdot and Exploit in 2005 (also from Chelyabinsk), and Damagelab in 2006.
A search in Constella for the Russian version of Kirtsov’s full name — Кирцов Максим Георгиевич — brings up multiple accounts registered to maksya@icloud.com.
A review of the digital footprint for maksya@icloud.com at osint.industries reveals this address was used a decade ago to register a still-active account at imageshack.com under the name x999xx. That account features numerous screenshots of financial statements from various banks, chat logs with other hackers, and even hacked websites.
x999xx’s Imageshack account includes screenshots of bank account balances from dozens of financial institutions, as well as chat logs with other hackers and pictures of homegrown weed.
Some of the photos in that Imageshack account also appear on Kirtsov’s Vkontakte page, including images of vehicles he owns, as well as pictures of potted marijuana plants. Kirtsov’s Vkontakte profile says that in 2012 he was a faculty member of the Ozersk Technological Institute National Research Nuclear University.
The Vkontakte page lists Kirtsov’s occupation as a website called ozersk[.]today, which on the surface appears to be a blog about life in Ozersk. However, in 2019 the security firm Recorded Future published a blog post which found this domain was being used to host a malicious Cobalt Strike server.
Cobalt Strike is a commercial network penetration testing and reconnaissance tool that is sold only to vetted partners. But stolen or ill-gotten Cobalt Strike licenses are frequently abused by cybercriminal gangs to help lay the groundwork for the installation of ransomware on a victim network.
In August 2023, x999xx posted a message on Exploit saying he was interested in buying a licensed version of Cobalt Strike. A month earlier, x999xx filed a complaint on Exploit against another forum member named Cobaltforce, an apparent onetime partner whose sudden and prolonged disappearance from the community left x999xx and others in the lurch. Cobaltforce recruited people experienced in using Cobalt Strike for ransomware operations, and offered to monetize access to hacked networks for a share of the profits.
DomainTools.com finds ozersk[.]today was registered to the email address dashin2008@yahoo.com, which also was used to register roughly two dozen other domains, including x999xx[.]biz. Virtually all of those domains were registered to Maxim Kirtsov from Ozersk. Below is a mind map used to track the identities mentioned in this story.
x999xx is a prolific member of the Russian webmaster forum “Gofuckbiz,” with more than 2,000 posts over nearly a decade, according to Intel 471. In one post from 2016, x999xx asked whether anyone knew where he could buy a heat lamp that simulates sunlight, explaining that one his pet rabbits had recently perished for lack of adequate light and heat. Mr. Kirtsov’s Vkontakte page includes several pictures of caged rabbits from 2015 and earlier.
Reached via email, Mr. Kirtsov acknowledged that he is x999xx. Kirtsov said he and his team are also regular readers of KrebsOnSecurity.
“We’re glad to hear and read you,” Kirtsov replied.
Asked whether he was concerned about the legal and moral implications of his work, Kirtsov downplayed his role in ransomware intrusions, saying he was more focused on harvesting data.
“I consider myself as committed to ethical practices as you are,” Kirtsov wrote. “I have also embarked on research and am currently mentoring students. You may have noticed my activities on a forum, which I assume you know of through information gathered from public sources, possibly using the new tool you reviewed.”
“Regarding my posts about selling access, I must honestly admit, upon reviewing my own actions, I recall such mentions but believe they were never actualized,” he continued. “Many use the forum for self-serving purposes, which explains why listings of targets for sale have dwindled — they simply ceased being viable.”
Kirtsov asserted that he is not interested in harming healthcare institutions, just in stealing their data.
“As for health-related matters, I was once acquainted with affluent webmasters who would pay up to $50 for every 1000 health-themed emails,” Kirtsov said. “Therefore, I had no interest in the more sensitive data from medical institutions like X-rays, insurance numbers, or even names; I focused solely on emails. I am proficient in SQL, hence my ease with handling data like IDs and emails. And i never doing spam or something like this.”
On the Russian crime forums, x999xx said he never targets anything or anyone in Russia, and that he has little to fear from domestic law enforcement agencies provided he remains focused on foreign adversaries.
x999xx’s lackadaisical approach to personal security mirrors that of Wazawaka, another top Russian access broker who sold access to countless organizations and even operated his own ransomware affiliate programs.
“Don’t shit where you live, travel local, and don’t go abroad,” Wazawaka said of his own personal mantra. “Mother Russia will help you. Love your country, and you will always get away with everything.”
In January 2022, KrebsOnSecurity followed clues left behind by Wazawaka to identify him as 32-year-old Mikhail Matveev from Khakassia, Russia. In May 2023, the U.S. Department of Justice indicted Matveev as a key figure in several ransomware groups that collectively extorted hundreds of millions of dollars from victim organizations. The U.S. State Department is offering a $10 million reward for information leading to the capture and/or prosecution of Matveev.
Perhaps in recognition that many top ransomware criminals are largely untouchable so long as they remain in Russia, western law enforcement agencies have begun focusing more on getting inside the heads of those individuals. These so-called “psyops” are aimed at infiltrating ransomware-as-a-service operations, disrupting major cybercrime services, and decreasing trust within cybercriminal communities.
When authorities in the U.S. and U.K. announced in February 2024 that they’d infiltrated and seized the infrastructure used by the infamous LockBit ransomware gang, they borrowed the existing design of LockBit’s victim shaming website to link instead to press releases about the takedown, and included a countdown timer that was eventually replaced with the personal details of LockBit’s alleged leader.
In May 2024, law enforcement agencies in the United States and Europe announced Operation Endgame, a coordinated action against some of the most popular cybercrime platforms for delivering ransomware and data-stealing malware. The Operation Endgame website also included a countdown timer, which served to tease the release of several animated videos that mimic the same sort of flashy, short advertisements that established cybercriminals often produce to promote their services online.
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.
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.