For nearly a dozen years, residents of South Carolina have been kept in the dark by state and federal investigators over who was responsible for hacking into the state’s revenue department in 2012 and stealing tax and bank account information for 3.6 million people. The answer may no longer be a mystery: KrebsOnSecurity found compelling clues suggesting the intrusion was carried out by the same Russian hacking crew that stole of millions of payment card records from big box retailers like Home Depot and Target in the years that followed.

Questions about who stole tax and financial data on roughly three quarters of all South Carolina residents came to the fore last week at the confirmation hearing of Mark Keel, who was appointed in 2011 by Gov. Nikki Haley to head the state’s law enforcement division. If approved, this would be Keel’s third six-year term in that role.

The Associated Press reports that Keel was careful not to release many details about the breach at his hearing, telling lawmakers he knows who did it but that he wasn’t ready to name anyone.

“I think the fact that we didn’t come up with a whole lot of people’s information that got breached is a testament to the work that people have done on this case,” Keel asserted.

A ten-year retrospective published in 2022 by The Post and Courier in Columbia, S.C. said investigators determined the breach began on Aug. 13, 2012, after a state IT contractor clicked a malicious link in an email. State officials said they found out about the hack from federal law enforcement on October 10, 2012.

KrebsOnSecurity examined posts across dozens of cybercrime forums around that time, and found only one instance of someone selling large volumes of tax data in the year surrounding the breach date.

On Oct. 7, 2012 — three days before South Carolina officials say they first learned of the intrusion — a notorious cybercriminal who goes by the handle “Rescator” advertised the sale of “a database of the tax department of one of the states.”

“Bank account information, SSN and all other information,” Rescator’s sales thread on the Russian-language crime forum Embargo read. “If you purchase the entire database, I will give you access to it.”

A week later, Rescator posted a similar offer on the exclusive Russian forum Mazafaka, saying he was selling information from a U.S. state tax database, without naming the state. Rescator said the data exposed included Social Security Number (SSN), employer, name, address, phone, taxable income, tax refund amount, and bank account number.

“There is a lot of information, I am ready to sell the entire database, with access to the database, and in parts,” Rescator told Mazafaka members. “There is also information on corporate taxpayers.”

On Oct. 26, 2012, the state announced the breach publicly. State officials said they were working with investigators from the U.S. Secret Service and digital forensics experts from Mandiant, which produced an incident report (PDF) that was later published by South Carolina Dept. of Revenue. KrebsOnSecurity sought comment from the Secret Service, South Carolina prosecutors, and Mr. Keel’s office. This story will be updated if any of them respond. Update: The Secret Service declined to comment.

On Nov. 18, 2012, Rescator told fellow denizens of the forum Verified he was selling a database of 65,000 records with bank account information from several smaller, regional financial institutions. Rescator’s sales thread on Verified listed more than a dozen database fields, including account number, name, address, phone, tax ID, date of birth, employer and occupation.

Asked to provide more context about the database for sale, Rescator told forum members the database included financial records related to tax filings of a U.S. state. Rescator added that there was a second database of around 80,000 corporations that included social security numbers, names and addresses, but no financial information.

The AP says South Carolina paid $12 million to Experian for identity theft protection and credit monitoring for its residents after the breach.

“At the time, it was one of the largest breaches in U.S. history but has since been surpassed greatly by hacks to Equifax, Yahoo, Home Depot, Target and PlayStation,” the AP’s Jeffrey Collins wrote.

As it happens, Rescator’s criminal hacking crew was directly responsible for the 2013 breach at Target and the 2014 hack of Home Depot. The Target intrusion saw Rescator’s cybercrime shops selling roughly 40 million stolen payment cards, and 56 million cards from Home Depot customers.

Who is Rescator? On Dec. 14, 2023, KrebsOnSecurity published the results of a 10-year investigation into the identity of Rescator, a.k.a. Mikhail Borisovich Shefel, a 36-year-old who lives in Moscow and who recently changed his last name to Lenin.

Mr. Keel’s assertion that somehow the efforts of South Carolina officials following the breach may have lessened its impact on citizens seems unlikely. The stolen tax and financial data appears to have been sold openly on cybercrime forums by one of the Russian underground’s most aggressive and successful hacking crews.

While there are no indications from reviewing forum posts that Rescator ever sold the data, his sales threads came at a time when the incidence of tax refund fraud was skyrocketing.

Tax-related identity theft occurs when someone uses a stolen identity and SSN to file a tax return in that person’s name claiming a fraudulent refund. Victims usually first learn of the crime after having their returns rejected because scammers beat them to it. Even those who are not required to file a return can be victims of refund fraud, as can those who are not actually owed a refund from the U.S. Internal Revenue Service (IRS).

According to a 2013 report from the Treasury Inspector General’s office, the IRS issued nearly $4 billion in bogus tax refunds in 2012, and more than $5.8 billion in 2013. The money largely was sent to people who stole SSNs and other information on U.S. citizens, and then filed fraudulent tax returns on those individuals claiming a large refund but at a different address.

It remains unclear why Shefel has never been officially implicated in the breaches at Target, Home Depot, or in South Carolina. It may be that Shefel has been indicted, and that those indictments remain sealed for some reason. Perhaps prosecutors were hoping Shefel would decide to leave Russia, at which point it would be easier to apprehend him if he believed no one was looking for him.

But all signs are that Shefel is deeply rooted in Russia, and has no plans to leave. In January 2024, authorities in Australia, the United States and the U.K. levied financial sanctions against 33-year-old Russian man Aleksandr Ermakov for allegedly stealing data on 10 million customers of the Australian health insurance giant Medibank.

A week after those sanctions were put in place, KrebsOnSecurity published a deep dive on Ermakov, which found that he co-ran a Moscow-based IT security consulting business along with Mikhail Shefel called Shtazi-IT.

A Google-translated version of Shtazi dot ru. Image: Archive.org.

In 2021, the exclusive Russian cybercrime forum Mazafaka was hacked. The leaked user database shows one of the forum’s founders was an attorney who advised Russia’s top hackers on the legal risks of their work, and what to do if they got caught. A review of this user’s hacker identities shows that during his time on the forums he served as an officer in the special forces of the GRU, the foreign military intelligence agency of the Russian Federation.

Launched in 2001 under the tagline “Network terrorism,” Mazafaka would evolve into one of the most guarded Russian-language cybercrime communities. The forum’s member roster included a Who’s Who of top Russian cybercriminals, and it featured sub-forums for a wide range of cybercrime specialities, including malware, spam, coding and identity theft.

One representation of the leaked Mazafaka database.

In almost any database leak, the first accounts listed are usually the administrators and early core members. But the Mazafaka user information posted online was not a database file per se, and it was clearly edited, redacted and restructured by whoever released it. As a result, it can be difficult to tell which members are the earliest users.

The original Mazafaka is known to have been launched by a hacker using the nickname “Stalker.” However, the lowest numbered (non-admin) user ID in the Mazafaka database belongs to another individual who used the handle “Djamix,” and the email address djamix@mazafaka[.]ru.

From the forum’s inception until around 2008, Djamix was one of its most active and eloquent contributors. Djamix told forum members he was a lawyer, and nearly all of his posts included legal analyses of various public cases involving hackers arrested and charged with cybercrimes in Russia and abroad.

“Hiding with purely technical parameters will not help in a serious matter,” Djamix advised Maza members in September 2007. “In order to ESCAPE the law, you need to KNOW the law. This is the most important thing. Technical capabilities cannot overcome intelligence and cunning.”

Stalker himself credited Djamix with keeping Mazafaka online for so many years. In a retrospective post published to Livejournal in 2014 titled, “Mazafaka, from conception to the present day,” Stalker said Djamix had become a core member of the community.

“This guy is everywhere,” Stalker said of Djamix. “There’s not a thing on [Mazafaka] that he doesn’t take part in. For me, he is a stimulus-irritant and thanks to him, Maza is still alive. Our rallying force!”

Djamix told other forum denizens he was a licensed attorney who could be hired for remote or in-person consultations, and his posts on Mazafaka and other Russian boards show several hackers facing legal jeopardy likely took him up on this offer.

“I have the right to represent your interests in court,” Djamix said on the Russian-language cybercrime forum Verified in Jan. 2011. “Remotely (in the form of constant support and consultations), or in person – this is discussed separately. As well as the cost of my services.”

WHO IS DJAMIX?

A search on djamix@mazafaka[.]ru at DomainTools.com reveals this address has been used to register at least 10 domain names since 2008. Those include several websites about life in and around Sochi, Russia, the site of the 2014 Winter Olympics, as well as a nearby coastal town called Adler. All of those sites say they were registered to an Aleksei Safronov from Sochi who also lists Adler as a hometown.

The breach tracking service Constella Intelligence finds that the phone number associated with those domains — +7.9676442212 — is tied to a Facebook account for an Aleksei Valerievich Safronov from Sochi. Mr. Safronov’s Facebook profile, which was last updated in October 2022, says his ICQ instant messenger number is 53765. This is the same ICQ number assigned to Djamix in the Mazafaka user database.

The Facebook account for Aleksey Safronov.

A “Djamix” account on the forum privetsochi[.]ru (“Hello Sochi”) says this user was born Oct. 2, 1970, and that his website is uposter[.]ru. This Russian language news site’s tagline is, “We Create Communication,” and it focuses heavily on news about Sochi, Adler, Russia and the war in Ukraine, with a strong pro-Kremlin bent.

Safronov’s Facebook profile also gives his Skype username as “Djamixadler,” and it includes dozens of photos of him dressed in military fatigues along with a regiment of soldiers deploying in fairly remote areas of Russia. Some of those photos date back to 2008.

In several of the images, we can see a patch on the arm of Safronov’s jacket that bears the logo of the Spetsnaz GRU, a special forces unit of the Russian military. According to a 2020 report from the Congressional Research Service, the GRU operates both as an intelligence agency — collecting human, cyber, and signals intelligence — and as a military organization responsible for battlefield reconnaissance and the operation of Russia’s Spetsnaz military commando units.

Mr. Safronov posted this image of himself on Facebook in 2016. The insignia of the GRU can be seen on his sleeve.

“In recent years, reports have linked the GRU to some of Russia’s most aggressive and public intelligence operations,” the CRS report explains. “Reportedly, the GRU played a key role in Russia’s occupation of Ukraine’s Crimea region and invasion of eastern Ukraine, the attempted assassination of former Russian intelligence officer Sergei Skripal in the United Kingdom, interference in the 2016 U.S. presidential elections, disinformation and propaganda operations, and some of the world’s most damaging cyberattacks.”

According to the Russia-focused investigative news outlet Meduza, in 2014 the Russian Defense Ministry created its “information-operation troops” for action in “cyber-confrontations with potential adversaries.”

“Later, sources in the Defense Ministry explained that these new troops were meant to ‘disrupt the potential adversary’s information networks,'” Meduza reported in 2018. “Recruiters reportedly went looking for ‘hackers who have had problems with the law.'”

Mr. Safronov did not respond to multiple requests for comment. A 2018 treatise written by Aleksei Valerievich Safronov titled “One Hundred Years of GRU Military Intelligence” explains the significance of the bat in the seal of the GRU.

“One way or another, the bat is an emblem that unites all active and retired intelligence officers; it is a symbol of unity and exclusivity,” Safronov wrote. “And, in general, it doesn’t matter who we’re talking about – a secret GRU agent somewhere in the army or a sniper in any of the special forces brigades. They all did and are doing one very important and responsible thing.”

It’s unclear what role Mr. Safronov plays or played in the GRU, but it seems likely the military intelligence agency would have exploited his considerable technical skills, knowledge and connections on the Russian cybercrime forums.

Searching on Safronov’s domain uposter[.]ru in Constella Intelligence reveals that this domain was used in 2022 to register an account at a popular Spanish-language discussion forum dedicated to helping applicants prepare for a career in the Guardia Civil, one of Spain’s two national police forces. Pivoting on that Russian IP in Constella shows three other accounts were created at the same Spanish user forum around the same date.

Mark Rasch is a former cybercrime prosecutor for the U.S. Department of Justice who now serves as chief legal officer for the New York cybersecurity firm Unit 221B. Rasch said there has always been a close relationship between the GRU and the Russian hacker community, noting that in the early 2000s the GRU was soliciting hackers with the skills necessary to hack US banks in order to procure funds to help finance Russia’s war in Chechnya.

“The guy is heavily hooked into the Russian cyber community, and that’s useful for intelligence services,” Rasch said. “He could have been infiltrating the community to monitor it for the GRU. Or he could just be a guy wearing a military uniform.”