Administrator of RSOCKS Proxy Botnet Pleads Guilty

Denis Emelyantsev, a 36-year-old Russian man accused of running a massive botnet called RSOCKS that stitched malware into millions of devices worldwide, pleaded guilty to two counts of computer crime violations in a California courtroom this week. The plea comes just months after Emelyantsev was extradited from Bulgaria, where he told investigators, “America is looking for me because I have enormous information and they need it.”

First advertised in the cybercrime underground in 2014, RSOCKS was the web-based storefront for hacked computers that were sold as “proxies” to cybercriminals looking for ways to route their Web traffic through someone else’s device.

Customers could pay to rent access to a pool of proxies for a specified period, with costs ranging from $30 per day for access to 2,000 proxies, to $200 daily for up to 90,000 proxies.

Many of the infected systems were Internet of Things (IoT) devices, including industrial control systems, time clocks, routers, audio/video streaming devices, and smart garage door openers. Later in its existence, the RSOCKS botnet expanded into compromising Android devices and conventional computers.

In June 2022, authorities in the United States, Germany, the Netherlands and the United Kingdom announced a joint operation to dismantle the RSOCKS botnet. But that action did not name any defendants.

Inspired by that takedown, KrebsOnSecurity followed clues from the RSOCKS botnet master’s identity on the cybercrime forums to Emelyantsev’s personal blog, where he went by the name Denis Kloster. The blog featured musings on the challenges of running a company that sells “security and anonymity services to customers around the world,” and even included a group photo of RSOCKS employees.

“Thanks to you, we are now developing in the field of information security and anonymity!,” Kloster’s blog enthused. “We make products that are used by thousands of people around the world, and this is very cool! And this is just the beginning!!! We don’t just work together and we’re not just friends, we’re Family.”

But by the time that investigation was published, Emelyantsev had already been captured by Bulgarian authorities responding to an American arrest warrant. At his extradition hearing, Emelyantsev claimed he would prove his innocence in an U.S. courtroom.

“I have hired a lawyer there and I want you to send me as quickly as possible to clear these baseless charges,” Emelyantsev told the Bulgarian court. “I am not a criminal and I will prove it in an American court.”

Emelyantsev was far more than just an administrator of a large botnet. Behind the facade of his Internet advertising company based in Omsk, Russia, the RSOCKS botmaster was a major player in the Russian email spam industry for more than a decade.

Some of the top Russian cybercrime forums have been hacked over the years, and leaked private messages from those forums show the RSOCKS administrator claimed ownership of the RUSdot spam forum. RUSdot is the successor forum to Spamdot, a far more secretive and restricted community where most of the world’s top spammers, virus writers and cybercriminals collaborated for years before the forum imploded in 2010.

Indeed, the very first mentions of RSOCKS on any Russian-language cybercrime forums refer to the service by its full name as the “RUSdot Socks Server.”

Email spam — and in particular malicious email sent via compromised computers — is still one of the biggest sources of malware infections that lead to data breaches and ransomware attacks. So it stands to reason that as administrator of Russia’s most well-known forum for spammers, Emelyantsev probably knows quite a bit about other top players in the botnet spam and malware community.

It remains unclear whether Emelyantsev made good on his promise to spill that knowledge to American investigators as part of his plea deal. The case is being prosecuted by the U.S. Attorney’s Office for the Southern District of California, which has not responded to a request for comment.

Emelyantsev pleaded guilty on Monday to two counts, including damage to protected computers and conspiracy to damage protected computers. He faces a maximum of 20 years in prison, and is currently scheduled to be sentenced on April 27, 2023.

Accused Russian RSOCKS Botmaster Arrested, Requests Extradition to U.S.

A 36-year-old Russian man recently identified by KrebsOnSecurity as the likely proprietor of the massive RSOCKS botnet has been arrested in Bulgaria at the request of U.S. authorities. At a court hearing in Bulgaria this month, the accused hacker requested and was granted extradition to the United States, reportedly telling the judge, “America is looking for me because I have enormous information and they need it.”

On June 22, KrebsOnSecurity published Meet the Administrators of the RSOCKS Proxy Botnet, which identified Denis Kloster, a.k.a. Denis Emelyantsev, as the apparent owner of RSOCKS, a collection of millions of hacked devices that were sold as “proxies” to cybercriminals looking for ways to route their malicious traffic through someone else’s computer.

A native of Omsk, Russia, Kloster came into focus after KrebsOnSecurity followed clues from the RSOCKS botnet master’s identity on the cybercrime forums to Kloster’s personal blog, which featured musings on the challenges of running a company that sells “security and anonymity services to customers around the world.” Kloster’s blog even included a group photo of RSOCKS employees.

“Thanks to you, we are now developing in the field of information security and anonymity!,” Kloster’s blog enthused. “We make products that are used by thousands of people around the world, and this is very cool! And this is just the beginning!!! We don’t just work together and we’re not just friends, we’re Family.”

The Bulgarian news outlet 24Chasa.bg reports that Kloster was arrested in June at a co-working space in the southwestern ski resort town of Bansko, and that the accused asked to be handed over to the American authorities.

“I have hired a lawyer there and I want you to send me as quickly as possible to clear these baseless charges,” Kloster reportedly told the Bulgarian court this week. “I am not a criminal and I will prove it in an American court.”

Launched in 2013, RSOCKS was shut down in June 2022 as part of an international investigation into the cybercrime service. According to the Justice Department, the RSOCKS botnet initially targeted Internet of Things (IoT) devices, including industrial control systems, time clocks, routers, audio/video streaming devices, and smart garage door openers; later in its existence, the RSOCKS botnet expanded into compromising additional types of devices, including Android devices and conventional computers, the DOJ said.

The Justice Department’s June 2022 statement about that takedown cited a search warrant from the U.S. Attorney’s Office for the Southern District of California, which also was named by Bulgarian news outlets this month as the source of Kloster’s arrest warrant.

When asked about the existence of an arrest warrant or criminal charges against Kloster, a spokesperson for the Southern District said, “no comment.”

Update, Sept. 24, 9:00 a.m. ET: Kloster was named in a 2019 indictment (PDF) unsealed Sept. 23 by the Southern District court.

24Chasa said the defendant’s surname is Emelyantsev and that he only recently adopted the last name Kloster, which is his mother’s maiden name.

As KrebsOnSecurity reported in June, Kloster also appears to be a major player in the Russian email spam industry. In several private exchanges on cybercrime forums, the RSOCKS administrator claimed ownership of the RUSdot spam forum. RUSdot is the successor forum to Spamdot, a far more secretive and restricted forum where most of the world’s top spammers, virus writers and cybercriminals collaborated for years before the community’s implosion in 2010.

Email spam — and in particular malicious email sent via compromised computers — is still one of the biggest sources of malware infections that lead to data breaches and ransomware attacks. So it stands to reason that as administrator of Russia’s most well-known forum for spammers, the defendant in this case probably knows quite a bit about other top players in the botnet spam and malware community.

Despite maintaining his innocence, Kloster reportedly told the Bulgarian judge that he could be useful to American investigators.

“America is looking for me because I have enormous information and they need it,” Kloster told the court, according to 24Chasa. “That’s why they want me.”

The Bulgarian court agreed, and granted his extradition. Kloster’s fiancee also attended the extradition hearing, and reportedly wept in the hall outside the entire time.

Kloster turned 36 while awaiting his extradition hearing, and may soon be facing charges that carry punishments of up to 20 years in prison.

The Link Between AWM Proxy & the Glupteba Botnet

On December 7, 2021, Google announced it was suing two Russian men allegedly responsible for operating the Glupteba botnet, a global malware menace that has infected millions of computers over the past decade. That same day, AWM Proxy — a 14-year-old anonymity service that rents hacked PCs to cybercriminals — suddenly went offline. Security experts had long seen a link between Glupteba and AWM Proxy, but new research shows AWM Proxy’s founder is one of the men being sued by Google.

Launched in March 2008, AWM Proxy quickly became the largest service for crooks seeking to route their malicious Web traffic through compromised devices. In 2011, researchers at Kaspersky Lab showed that virtually all of the hacked systems for rent at AWM Proxy had been compromised by TDSS (a.k.a TDL-4 and Alureon), a stealthy “rootkit” that installs deep within infected PCs and loads even before the underlying Windows operating system boots up.

In March 2011, security researchers at ESET found TDSS was being used to deploy Glupteba, another rootkit that steals passwords and other access credentials, disables security software, and tries to compromise other devices on the victim’s network — such as Internet routers and media storage servers — for use in relaying spam or other malicious traffic.

Like its predecessor TDSS, Glupteba is primarily distributed through “pay-per-install” or PPI networks, and via traffic purchased from traffic distribution systems (TDS). Pay-per-install networks try to match cybercriminals who already have access to large numbers of hacked PCs with other crooks seeking broader distribution of their malware.

In a typical PPI network, clients will submit their malware—a spambot or password-stealing Trojan, for example —to the service, which in turn charges per thousand successful installations, with the price depending on the requested geographic location of the desired victims. One of the most common ways PPI affiliates generate revenue is by secretly bundling the PPI network’s installer with pirated software titles that are widely available for download via the web or from file-sharing networks.

Over the past decade, both Glupteba and AWM Proxy have grown substantially. When KrebsOnSecurity first covered AWM Proxy in 2011, the service was selling access to roughly 24,000 infected PCs scattered across dozens of countries. Ten years later, AWM Proxy was offering 10 times that number of hacked systems on any given day, and Glupteba had grown to more than one million infected devices worldwide.

There is also ample evidence to suggest that Glupteba may have spawned Meris, a massive botnet of hacked Internet of Things (IoT) devices that surfaced in September 2021 and was responsible for some of the largest and most disruptive distributed denial-of-service (DDoS) attacks the Internet has ever seen.

But on Dec. 7, 2021, Google announced it had taken technical measures to dismantle the Glupteba botnet, and filed a civil lawsuit (PDF) against two Russian men thought to be responsible for operating the vast crime machine. AWM Proxy’s online storefront disappeared that same day.

AWM Proxy quickly alerted its customers that the service had moved to a new domain, with all customer balances, passwords and purchase histories seamlessly ported over to the new home. However, subsequent takedowns targeting AWM Proxy’s domains and other infrastructure have conspired to keep the service on the ropes and frequently switching domains ever since.

Earlier this month, the United States, Germany, the Netherlands and the U.K. dismantled the “RSOCKS” botnet, a competing proxy service that had been in operation since 2014. KrebsOnSecurity has identified the owner of RSOCKS as a 35-year-old from Omsk, Russia who runs the world’s largest forum catering to spammers.

Shortly after last week’s story on the RSOCKS founder, I heard from Riley Kilmer, co-founder of Spur.us, a startup that tracks criminal proxy services. Kilmer said RSOCKS was similarly disabled after Google’s combined legal sneak attack and technical takedown targeting Glupteba.

“The RSOCKS website gave you the estimated number of proxies in each of their subscription packages, and that number went down to zero on Dec. 7,” Kilmer said. “It’s not clear if that means the services were operated by the same people, or if they were just using the same sources (i.e., PPI programs) to generate new installations of their malware.”

Kilmer said each time his company tried to determine how many systems RSOCKS had for sale, they found each Internet address being sold by RSOCKS was also present in AWM Proxy’s network. In addition, Kilmer said, the application programming interfaces (APIs) used by both services to keep track of infected systems were virtually identical, once again suggesting strong collaboration.

“One hundred percent of the IPs we got back from RSOCKS we’d already identified in AWM,” Kilmer said. “And the IP port combinations they give you when you access an individual IP were the same as from AWM.”

In 2011, KrebsOnSecurity published an investigation that identified one of the founders of AWM Proxy, but Kilmer’s revelation prompted me to take a fresh look at the origins of this sprawling cybercriminal enterprise to determine if there were additional clues showing more concrete links between RSOCKS, AWM Proxy and Glupteba.

IF YOUR PLAN IS TO RIP OFF GOOGLE…

Supporting Kilmer’s theory that AWM Proxy and RSOCKS may simply be using the same PPI networks to spread, further research shows the RSOCKS owner also had an ownership stake in AD1[.]ru, an extremely popular Russian-language pay-per-install network that has been in operation for at least a decade.

Google took aim at Glupteba in part because its owners were using the botnet to divert and steal vast sums in online advertising revenue. So it’s more than a little ironic that the critical piece of evidence linking all of these operations begins with a Google Analytics code included in the HTML code for the original AWM Proxy back in 2008 (UA-3816536).

That analytics code also was present on a handful of other sites over the years, including the now-defunct Russian domain name registrar Domenadom[.]ru, and the website web-site[.]ru, which curiously was a Russian company operating a global real estate appraisal business called American Appraisal.

Two other domains connected to that Google Analytics code — Russian plastics manufacturers techplast[.]ru and tekhplast.ru — also shared a different Google Analytics code (UA-1838317) with web-site[.]ru and with the domain “starovikov[.]ru.”

The name on the WHOIS registration records for the plastics domains is an “Alexander I. Ukraincki,” whose personal information also is included in the domains tpos[.]ru and alphadisplay[.]ru, both apparently manufacturers of point-of-sale payment terminals in Russia.

Constella Intelligence, a security firm that indexes passwords and other personal information exposed in past data breaches, revealed dozens of variations on email addresses used by Alexander I. Ukraincki over the years. Most of those email addresses start with some variation of “uai@” followed by a domain from one of the many Russian email providers (e.g., yandex.ru, mail.ru). [Full disclosure: Constella is currently an advertiser on this website].

But Constella also shows those different email addresses all relied on a handful of passwords — most commonly “2222den” and “2222DEN.” Both of those passwords have been used almost exclusively in the past decade by the person who registered more than a dozen email addresses with the username “dennstr.”

The dennstr identity leads to several variations on the same name — Denis Strelinikov, or Denis Stranatka, from Ukraine, but those clues ultimately led nowhere promising. And maybe that was the point.

Things began looking brighter after I ran a search in DomainTools for web-site[.]ru’s original WHOIS records, which shows it was assigned in 2005 to a “private person” who used the email address lycefer@gmail.com. A search in Constella on that email address says it was used to register nearly two dozen domains, including starovikov.ru and starovikov[.]com.

A cached copy of the contact page for Starovikov[.]com shows that in 2008 it displayed the personal information for a Dmitry Starovikov, who listed his Skype username as “lycefer.”

Finally, Russian incorporation documents show the company LLC Website (web-site[.]ru)was registered in 2005 to two men, one of whom was named Dmitry Sergeevich Starovikov.

Bringing this full circle, Google says Starovikov is one of the two operators of the Glupteba botnet:

Mr. Starovikov did not respond to requests for comment. But attorneys for Starovikov and his co-defendant last month filed a response to Google’s complaint in the Southern District of New York, denying (PDF) their clients had any knowledge of the scheme.

Despite all of the disruption caused by Google’s legal and technical meddling, AWM is still around and nearly as healthy as ever, although the service has been branded with a new name and there are dubious claims of new owners. Advertising customer plans ranging from $50 a day to nearly $700 for “VIP access,” AWM Proxy says its malware has been running on approximately 175,000 systems worldwide over the last 24 hours, and that roughly 65,000 of these systems are currently online.

Meanwhile, the administrators of RSOCKS recently alerted customers that the service and any unspent balances will soon be migrated over to a new location.

Many people seem to equate spending time, money and effort to investigate and prosecute cybercriminals with the largely failed war on drugs, meaning there is an endless supply of up-and-coming crooks who will always fill in any gaps in the workforce whenever cybercriminals face justice.

While that may be true for many low-level cyber thieves today, investigations like these show once again how small the cybercriminal underground really is. It also shows how it makes a great deal of sense to focus efforts on targeting and disrupting the relatively small number of established hackers who remain the real force multipliers of cybercrime.

Meet the Administrators of the RSOCKS Proxy Botnet

Authorities in the United States, Germany, the Netherlands and the U.K. last week said they dismantled the “RSOCKS” botnet, a collection of millions of hacked devices that were sold as “proxies” to cybercriminals looking for ways to route their malicious traffic through someone else’s computer. While the coordinated action did not name the Russian hackers allegedly behind RSOCKS, KrebsOnSecurity has identified its owner as a 35-year-old Russian man living abroad who also runs the world’s top spam forum.

According to a statement by the U.S. Department of Justice, RSOCKS offered clients access to IP addresses assigned to devices that had been hacked:

“A cybercriminal who wanted to utilize the RSOCKS platform could use a web browser to navigate to a web-based ‘storefront’ (i.e., a public web site that allows users to purchase access to the botnet), which allowed the customer to pay to rent access to a pool of proxies for a specified daily, weekly, or monthly time period. The cost for access to a pool of RSOCKS proxies ranged from $30 per day for access to 2,000 proxies to $200 per day for access to 90,000 proxies.”

The DOJ’s statement doesn’t mention that RSOCKS has been in operation since 2014, when access to the web store for the botnet was first advertised on multiple Russian-language cybercrime forums.

The user “RSOCKS” on the Russian crime forum Verified changed his name to RSOCKS from a previous handle: “Stanx,” whose very first sales thread on Verified in 2016 quickly ran afoul of the forum’s rules and prompted a public chastisement by the forum’s administrator.

Verified was hacked twice in the past few years, and each time the private messages of all users on the forum were leaked. Those messages show that after being warned of his forum infraction, Stanx sent a private message to the Verified administrator detailing his cybercriminal bona fides.

“I am the owner of the RUSdot forum (former Spamdot),” Stanx wrote in Sept. 2016. “In spam topics, people know me as a reliable person.”

RUSdot is the successor forum to Spamdot, a far more secretive and restricted forum where most of the world’s top spammers, virus writers and cybercriminals collaborated for years before the community’s implosion in 2010. Even today, the RUSdot Mailer is advertised for sale at the top of the RUSdot community forum.

Stanx said he was a longtime member of several major forums, including the Russian hacker forum Antichat (since 2005), and the Russian crime forum Exploit (since April 2013). In an early post to Antichat in January 2005, Stanx disclosed that he is from Omsk, a large city in the Siberian region of Russia.

According to the cyber intelligence firm Intel 471, the user Stanx indeed registered on Exploit in 2013, using the email address stanx@rusdot.com, and the ICQ number 399611. A search in Google for that ICQ number turns up a cached version of a Vkontakte profile for a Denis “Neo” Kloster, from Omsk, Russia.

Cybersecurity firm Constella Intelligence shows that in 2017, someone using the email address istanx@gmail.com registered at the Russian freelancer job site fl.ru with the profile name of “Denis Kloster” and the Omsk phone number of 79136334444. Another record indexed by Constella suggests Denis’s real surname may in fact be “Emilyantsev” [Емельянцев].

That phone number is tied to the WHOIS registration records for multiple domain names over the years, including proxy[.]info, allproxy[.]info, kloster.pro and deniskloster.com.

The “about me” section of DenisKloster.com says the 35-year-old was born in Omsk, that he got his first computer at age 12, and graduated from high school at 16. Kloster says he’s worked in many large companies in Omsk as a system administrator, web developer and photographer.

According to Kloster’s blog, his first real job was running an “online advertising” firm he founded called Internet Advertising Omsk (“riOmsk“), and that he even lived in New York City for a while.

“Something new was required and I decided to leave Omsk and try to live in the States,” Kloster wrote in 2013. “I opened an American visa for myself, it was not difficult to get. And so I moved to live in New York, the largest city in the world, in a country where all wishes come true. But even this was not enough for me, and since then I began to travel the world.”

The current version of the About Me page on Kloster’s site says he closed his advertising business in 2013 to travel the world and focus on his new company: One that provides security and anonymity services to customers around the world. Kloster’s vanity website and LinkedIn page both list him as CEO of a company called “SL MobPartners.”

In 2016, Deniskloster.com featured a post celebrating three years in operation. The anniversary post said Kloster’s anonymity business had grown to nearly two dozen employees, most of whom were included in a group photo posted to that article (and some of whom Kloster thanked by their first names and last initials).

“Thanks to you, we are now developing in the field of information security and anonymity!,” the post enthuses. “We make products that are used by thousands of people around the world, and this is very cool! And this is just the beginning!!! We don’t just work together and we’re not just friends, we’re Family.”

Mr. Kloster did not respond to repeated requests for comment.

It’s not clear if the coordinated takedown targeting the RSOCKS botnet will be permanent, as the botnet’s owners could simply rebuild — and possibly rebrand — their crime machine. Based on the RSOCKS owner’s posts, that is exactly what they intend to do.

“RSocks ceases to exist,” wrote the Rsocks account on the BlackHatWorld forum on June 17. “But don’t worry. All the active plans and fund balances will be transferred to another service. Stay tuned. We will inform you about its name and all the details later.”

Malware-based proxy services like RSOCKS have struggled to remain competitive in a cybercrime market with increasingly sophisticated proxy services that offer many additional features. The demise of RSOCKS follows closely on the heels of VIP72[.]com, a competing proxy botnet service that operated for a decade before its owners pulled the plug on the service last year.

Authorities Shut Down Russian RSOCKS Botnet That Hacked Millions of Devices

The U.S. Department of Justice (DoJ) on Thursday disclosed that it took down the infrastructure associated with a Russian botnet known as RSOCKS in collaboration with law enforcement partners in Germany, the Netherlands, and the U.K. The botnet, operated by a sophisticated cybercrime organization, is believed to have ensnared millions of internet-connected devices, including Internet of Things (