Posts Tagged: Gameover ZeuS

Sep 15

Arrests Tied to Citadel, Dridex Malware

Authorities in Europe have arrested alleged key players behind the development and deployment of sophisticated banking malware, including Citadel and Dridex. The arrests involved a Russian national and a Moldovan man, both of whom were traveling or residing outside of their native countries and are now facing extradition to the United States.

cuffedLast week, a 30-year-old from Moldova who was wanted by U.S. authorities was arrested in Paphos — a coastal vacation spot in Cyprus where the accused was reportedly staying with his wife. A story in the Cyprus Mail has few other details about the arrest, other than to say authorities believe the man was responsible for more than $3.5 million in bank fraud using a PC.

Sources close to the investigation say the man is a key figure in an organized crime gang responsible for developing and using a powerful banking Trojan known as “Dridex” (a.k.a. Cridex, Bugat). The Dridex gang is thought to have spun off from the “Business Club,” an Eastern European organized cybercrime gang accused of stealing more than $100 million from banks and businesses worldwide.

In June 2014, the U.S. Justice Department joined multiple international law enforcement agencies and security firms in taking down the Business Club’s key asset: The Gameover ZeuS botnet, an ultra-sophisticated, global crime machine that infected upwards of a half-million PCs and was used in countless cyberheists. Dridex would first emerge in July 2014, a month after the Gameover Zeus botnet was dismantled.

Separately, the press in Norway writes about a 27-year-old Russian man identified only as “Mark” who was reportedly arrested in the Norwegian town of Fredrikstad at the request of the FBI. The story notes that American authorities believe Mark is the software developer behind Citadel, a malware-as-a-service product that played a key role in countless cyberheists against American and European small businesses.

For example, Citadel was thought to have been the very same malware used to steal usernames and passwords from a Pennsylvania heating and air conditioning vendor; those same stolen credentials were reportedly leveraged in the breach that resulted in the theft of nearly 40 million credit cards from Target Corp. in November and December of 2013.

The Norwegian newspaper VG writes that Mark has been held under house arrest for the past 11 months, while the FBI tries to work out his extradition to the United States. His detention is being fought by Russia, which is naturally opposed to the treatment he may receive in the United States and says the evidence against Mark is scant.

According to VG, the U.S. Justice Department believes Mark is none other than “Aquabox,” the nickname chosen by the proprietor of the Citadel malware, which was created based off of the source code for the ZeuS Trojan malware. Citadel was sold and marketed as a service that let buyers and users interact with the developer and one another, to solicit feedback on how to fix bugs in the malware program, and to request new features in the malware going forward.

For a full translation of the original Citadel sales pitch as penned by Aquabox in 2011, see this link (PDF). For a full translated version of the VG story on Mark, see this PDF (thanks to KrebsOnSecurity reader Jeevan Sivagnanasuntharam for helping with the translation). VG notes that Mark continues to maintain his innocence. [Side note: The Citadel malware has for years had in its code a dig directed at the author of this blog: Included in the guts of the Trojan is the text string, “Coded by BRIAN KREBS for personal use only. I love my job & wife.” Needless to say, the second part of that statement is true, but Citadel was not coded by this Brian Krebs.]

A text string inside of the Citadel trojan. Source: AhnLab

A text string inside of the Citadel trojan. Source: AhnLab

Ars Technica carries an interesting piece about Deniss Calovskis, a Latvian man who was arrested in February and extradited to the United States for his role in creating the Gozi virus, another powerful malware family that has been used in countless cyberheists. The 30-year-old Calovskis long maintained his innocence, but ultimately acknowledged his role in a guilty plea entered in a federal court in Manhattan last week. Continue reading →

Aug 15

Inside the $100M ‘Business Club’ Crime Gang

New research into a notorious Eastern European organized cybercrime gang accused of stealing more than $100 million from banks and businesses worldwide provides an unprecedented, behind-the-scenes look at an exclusive “business club” that dabbled in cyber espionage and worked closely with phantom Chinese firms on Russia’s far eastern border.

In the summer of 2014, the U.S. Justice Department joined multiple international law enforcement agencies and security firms in taking down the Gameover ZeuS botnet, an ultra-sophisticated, global crime machine that infected upwards of a half-million PCs.

Thousands of freelance cybercrooks have used a commercially available form of the ZeuS banking malware for years to siphon funds from Western bank accounts and small businesses. Gameover ZeuS, on the other hand, was a closely-held, customized version secretly built by the ZeuS author himself (following a staged retirement) and wielded exclusively by a cadre of hackers that used the systems in countless online extortion attacks, spam and other illicit moneymaking schemes.

Last year’s takedown of the Gameover ZeuS botnet came just months after the FBI placed a $3 million bounty on the botnet malware’s alleged author — a Russian programmer named Evgeniy Mikhailovich Bogachev who used the hacker nickname “Slavik.” But despite those high-profile law enforcement actions, little has been shared about the day-to-day operations of this remarkably resourceful cybercrime gang.

That changed today with the release of a detailed report from Fox-IT, a security firm based in the Netherlands that secretly gained access to a server used by one of the group’s members. That server, which was rented for use in launching cyberattacks, included chat logs between and among the crime gang’s core leaders, and helped to shed light on the inner workings of this elite group.

The alleged ZeuS Trojan author, Yevgeniy Bogachev, Evgeniy Mikhaylovich Bogachev, a.k.a. "lucky12345", "slavik", "Pollingsoon". Source: "most wanted, cyber.

The alleged ZeuS Trojan author, Yevgeniy Bogachev, Evgeniy Mikhaylovich Bogachev, a.k.a. “lucky12345”, “slavik”, “Pollingsoon”. Source: “most wanted, cyber.


The chat logs show that the crime gang referred to itself as the “Business Club,” and counted among its members a core group of a half-dozen people supported by a network of more than 50 individuals. In true Oceans 11 fashion, each Business Club member brought a cybercrime specialty to the table, including 24/7 tech support technicians, third-party suppliers of ancillary malicious software, as well as those engaged in recruiting “money mules” — unwitting or willing accomplices who could be trained or counted on to help launder stolen funds.

“To become a member of the business club there was typically an initial membership fee and also typically a profit sharing agreement,” Fox-IT wrote. “Note that the customer and core team relationship was entirely built on trust. As a result not every member would directly get full access, but it would take time until all the privileges of membership would become available.”

Michael Sandee, a principal security expert at Fox-IT and author of the report, said although Bogachev and several other key leaders of the group were apparently based in or around Krasnodar — a temperate area of Russia on the Black Sea — the crime gang had members that spanned most of Russia’s 11 time zones.

Geographic diversity allowed the group — which mainly worked regular 9-5 hour days Monday through Friday — to conduct their cyberheists against banks by following the rising sun across the globe — emptying accounts at Australia and Asian banks in the morning there, European banks in the afternoon, before handing the operations over to a part of the late afternoon team based in Eastern Europe that would attempt to siphon funds from banks that were just starting their business day in the United States.

“They would go along with the time zone, starting with banks in Australia, then continuing in Asia and following the business day wherever it was, ending the day with [attacks against banks in] the United States,” Sandee said.



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Feb 15

FBI: $3M Bounty for ZeuS Trojan Author

The FBI this week announced it is offering a USD $3 million bounty for information leading to the arrest and/or conviction of one Evgeniy Mikhailovich Bogachev, a Russian man the government believes is responsible for building and distributing the ZeuS banking Trojan.

Bogachev is thought to be a core architect of ZeuS, a malware strain that has been used to steal hundreds of millions of dollars from bank accounts — mainly from small- to mid-sized businesses based in the United States and Europe. Bogachev also is accused of being part of a crime gang that infected tens of millions of computers, harvested huge volumes of sensitive financial data, and rented the compromised systems to other hackers, spammers and online extortionists.

So much of the intelligence gathered about Bogachev and his alleged accomplices has been scattered across various court documents and published reports over the years, but probably just as much on this criminal mastermind and his associates has never seen the light of day. What follows is a compendium of knowledge — a bit of a dossier, if you will — on Bogachev and his trusted associates.

I first became aware of Bogachev by his nickname at the time –“Slavik” — in June 2009, after writing about a $415,000 cyberheist against Bullitt County, Kentucky. I was still working for The Washington Post then, but that story would open the door to sources who were tracking the activities of an organized cybercrime gang that spanned from Ukraine and Russia to the United Kingdom.

Yevgeniy Bogachev, Evgeniy Mikhaylovich Bogachev, a.k.a. "lucky12345", "slavik", "Pollingsoon". Source: "most wanted, cyber.

Yevgeniy Bogachev, Evgeniy Mikhaylovich Bogachev, a.k.a. “lucky12345”, “slavik”, “Pollingsoon”. Source: “most wanted, cyber.

Not long after that Bullitt County cyberheist story ran, I heard from a source who’d hacked the Jabber instant message server that these crooks were using to plan and coordinate their cyberheists. The members of this crew quickly became regular readers of my Security Fix blog at The Post after seeing their exploits detailed on the blog.

bullittcar-thumb-250x110They also acknowledged in their chats that they’d been in direct contact with the Zeus author himself — and that the gang had hired the malware author to code a custom version of the Trojan that would latter become known as “Jabberzeus.” The “jabber” part of the name is a reference to a key feature of the malware that would send an Jabber instant message to members of the gang anytime a new victim logged into a bank account that had a high balance.

Here’s a snippet from that chat, translated from Russian. “Aqua” was responsible for recruiting and managing a network of “money mules” to help cash out the payroll accounts that these crooks were hijacking with the help of their custom Jabberzeus malware. “Dimka” is Aqua’s friend, and Aqua explains to him that they hired the ZeuS author to create the custom malware and help them troubleshoot it. But Aqua is unhappy because the ZeuS author declined to help them keep it undetectable by commercial antivirus tools.

dimka: I read about the king of seas, was that your handiwork?

aqua: what are you talking about?

dimka: zeus

aqua: yes, we are using it right now. its developer sits with us on the system

dimka: it seems to be very popular right now

aqua: but that fucker annoyed the hell out of everyone. he refuses to write bypass of [anti-malware] scans, and trojan penetration is only 35-40%. we need better

aqua: read this. here you find almost everything about us

aqua: we’re using this [custom] system. we are the Big Dog. the rest using Zeus are doing piddly crap.

Days later, other members of the Jabberzeus crew  were all jabbering about the Bullitt County cyberheist story. The individual who uses the nickname “tank” in the conversation below managed money mules for the gang and helped coordinate the exchange of stolen banking credentials. Tank begins the conversation by pasting a link to my Washington Post story about the Bullitt County hack. That is about us. Only the figures are fairytales. This was from your botnet account. Apparently, this is why our hosters in service rejected the old ones. They caused a damn commotion. I have already become paranoid over this. Such bullshit as this in the Washington Post. I almost dreamed of this bullshit at night. He writes about everything that I touch in any manner…Klik Partners, ESTHost, MCCOLO… Now you are not alone.  Just 2 weeks before this I contacted him as an expert to find out anything new. It turns out that he wrote this within 3 days. Now we also will dream about him.

In a separate conversation between Tank and the Zeus author (using the nickname “lucky12345” here), the two complain about news coverage of Zeus:

tank: Are you there?

tank: This is what they damn wrote about me.

tank: [pasting a link to the Washington Post story]

tank: I’ll take a quick look at history

tank: Originator: BULLITT COUNTY FISCAL Company: Bullitt County Fiscal Court

tank: Well, you got it from that cash-in.

lucky12345: From 200k?

tank: Well, they are not the right amounts and the cash out from that account was shitty.

tank: Levak was written there.

tank: Because now the entire USA knows about Zeus.

tank: :(

lucky12345: It’s fucked.

After the Bullitt County story, my source and I tracked this gang as they hit one small business after another. In the ensuing six months before my departure from The Post, I wrote about this gang’s attacks against more than a dozen companies in the United States.

By this time, Slavik was openly selling the barebones ZeuS Trojan code that Jabberzeus was built on to anyone who could pay several thousand dollars for the crimeware kit. There is evidence he also was using his own botnet kit or at least taking a fee to set up instances of it on behalf of buyers. In late 2009, security researchers had tracked dozens of Zeus control servers that phoned home to domains which bore his nickname, such as, slavik1[dot]com, slavik2[dot]com, slavik3[dot]com, and so on. Continue reading →

Aug 14

New Site Recovers Files Locked by Cryptolocker Ransomware

Until today, Microsoft Windows users who’ve been unfortunate enough to have the personal files on their computer encrypted and held for ransom by a nasty strain of malware called CryptoLocker have been faced with a tough choice: Pay cybercrooks a ransom of a few hundred to several thousand dollars to unlock the files, or kiss those files goodbye forever. That changed this morning, when two security firms teamed up to launch a free new online service that can help victims unlock and recover files scrambled by the malware.

clssFirst spotted in September 2013, CryptoLocker is a prolific and very damaging strain of malware that uses strong encryption to lock files that are likely to be the most valued by victim users, including Microsoft Office documents, photos, and MP3 files.

Infected machines typically display a warning that the victim’s files have been locked and can only be decrypted by sending a certain fraction or number of Bitcoins to a decryption service run by the perpetrators. Victims are given 72 hours to pay the ransom — typically a few hundred dollars worth of Bitcoins — after which time the ransom demand increases fivefold or more.

But early Wednesday morning, two security firms – Milpitas, Calf. based FireEye and Fox-IT in the Netherlands — launched, a site that victims can use to recover their files. Victims need to provide an email address and upload just one of the encrypted files from their computer, and the service will email a link that victims can use to download a recovery program to decrypt all of their scrambled files.

The free decryption service was made possible because Fox-IT was somehow able to recover the private keys that the cybercriminals who were running the CryptoLocker scam used on their own (not free) decryption service. Neither company is disclosing much about how exactly those keys were recovered other than to say that the opportunity arose as the crooks were attempting to recover from Operation Tovar, an international effort in June that sought to dismantle the infrastructure that CryptoLocker used to infect PCs.

Continue reading →

Jul 14

Crooks Seek Revival of ‘Gameover Zeus’ Botnet

Cybercrooks today began taking steps to resurrect the Gameover ZeuS botnet, a complex crime machine that has been blamed for the theft more than $100 million from banks, businesses and consumers worldwide. The revival attempt comes roughly five weeks after the FBI joined several nations, researchers and security firms in a global and thus far successful effort to eradicate it. gameover

The researchers who helped dismantle Gameover Zeus said they were surprised that the botmasters didn’t fight back. Indeed, for the past month the crooks responsible seem to have kept a low profile.

But that changed earlier this morning when researchers at Malcovery [full disclosure: Malcovery is an advertiser on this blog] began noticing spam being blasted out with phishing lures that included zip files booby-trapped with malware.

Looking closer, the company found that the malware shares roughly 90 percent of its code base with Gameover Zeus. Part of what made the original GameOver ZeuS so difficult to shut down was its reliance in part on an advanced peer-to-peer (P2P) mechanism to control and update the bot-infected systems.

But according to Gary Warner, Malcovery’s co-founder and chief technologist, this new Gameover variant is stripped of the P2P code, and relies instead on an approach known as fast-flux hosting. Fast-flux is a kind of round-robin technique that lets botnets hide phishing and malware delivery sites behind an ever-changing network of compromised systems acting as proxies, in a bid to make the botnet more resilient to takedowns. Continue reading →

Jun 14

Backstage with the Gameover Botnet Hijackers

When you’re planning to rob the Russian cyber mob, you’d better make sure that you have the element of surprise, that you can make a clean getaway, and that you understand how your target is going to respond. Today’s column features an interview with two security experts who helped plan and execute last week’s global, collaborative effort to hijack the Gameover Zeus botnet, an extremely resilient and sophisticated crime machine that helped an elite group of thieves steal more than $100 million from banks, businesses and consumers worldwide.

Gameover infections on June 4. Source:

Gameover infections on June 4, 2014. Source:

Neither expert I spoke with wished to be identified for this story, citing a lack of permission from their employers and a desire to remain off the radar of the crooks inconvenienced by the action. For obvious reasons, they were also reluctant to share details about the exact weaknesses that were used to hijack the botnet, focusing instead on the planning and and preparation that went into this effort.


A quick review of how Gameover works should help readers get more out of the interview. In traditional botnets, infected PCs report home to and are controlled by a central server. But this architecture leaves such botnets vulnerable to disruption or takeover if authorities or security experts can gain access to the control server.

Gameover, on the other hand, is a peer-to-peer (P2P) botnet designed as a collection of small networks that are distinct but linked up in a decentralized fashion. The individual Gameover-infected PCs are known as “peers.” Above the peers are a select number of slightly more powerful and important infected systems that are assigned roles as “proxy nodes,” meaning they were selected from the peers to serve as relay points for commands coming from the Gameover botnet operators and as conduits for encrypted data stolen from the infected systems.

The basic network structure of the Gameover botnet. Source: FBI

The basic network structure of the Gameover botnet. Source: FBI

The Gameover botnet code also includes a failsafe mechanism that can be invoked if the botnet’s P2P communications system fails, whether the failure is the result of a faulty malware update or because of a takedown effort by researchers/law enforcement. That failsafe is a domain generation algorithm (DGA) component that generates a list of 1,000 domain names each week (gibberish domains that are essentially long jumbles of letters) combined with one of six top-level domains; .com, .net, .org, .biz, .info and .ru. In the event the infected Gameover systems can’t get new instructions from their peers, the code instructs the botted systems to seek out domains from the latest list of 1,000 domains generated by the DGA until it finds a site with new instructions.


The Gameover malware was designed specifically to defeat two-factor authentication used by many banks. It did so using a huge collection of custom-made scripts known as “Web injects” that can inject custom content into a Web browser when the victim browses to certain sites — such as a specific bank’s login page. Web injects also are used to prompt the victim to enter additional personal information when they log in to a trusted site. An example of this type of Web inject can be seen in the video below, which shows an inject designed for Citibank customers. Continue reading →

Jun 14

‘Operation Tovar’ Targets ‘Gameover’ ZeuS Botnet, CryptoLocker Scourge

The U.S. Justice Department is expected to announce today an international law enforcement operation to seize control over the Gameover ZeuS botnet, a sprawling network of hacked Microsoft Windows computers that currently infects an estimated 500,000 to 1 million compromised systems globally. Experts say PCs infected with Gameover are being harvested for sensitive financial and personal data, and rented out to an elite cadre of hackers for use in online extortion attacks, spam and other illicit moneymaking schemes.

This graphic, from 2012, shows the decentralized nature of P2P network connectivity of 23,196 PCs infected with Gameover.  Image: Dell SecureWorks

This graphic, from 2012, shows the decentralized nature of P2P network connectivity of 23,196 PCs infected with Gameover. Image: Dell SecureWorks

The sneak attack on Gameover, dubbed “Operation Tovar,” began late last week and is a collaborative effort by investigators at the FBI, Europol, and the UK’s National Crime Agency; security firms CrowdStrike, Dell SecureWorks, SymantecTrend Micro and McAfee; and academic researchers at VU University Amsterdam and Saarland University in Germany. News of the action first came to light in a blog post published briefly on Friday by McAfee, but that post was removed a few hours after it went online.

Gameover is based on code from the ZeuS Trojan, an infamous family of malware that has been used in countless online banking heists. Unlike ZeuS — which was sold as a botnet creation kit to anyone who had a few thousand dollars in virtual currency to spend — Gameover ZeuS has since October 2011 been controlled and maintained by a core group of hackers from Russia and Ukraine.

Those individuals are believed to have used the botnet in high-dollar corporate account takeovers that frequently were punctuated by massive distributed-denial-of-service (DDoS) attacks intended to distract victims from immediately noticing the thefts. According to the Justice Department, Gameover has been implicated in the theft of more than $100 million in account takeovers.

The curators of Gameover also have reportedly loaned out sections of their botnet to vetted third-parties who have used them for a variety of purposes. One of the most popular uses of Gameover has been as a platform for seeding infected systems with CryptoLocker, a nasty strain of malware that locks your most precious files with strong encryption until you pay a ransom demand.

According to a 2012 research paper published by Dell SecureWorks, the Gameover Trojan is principally spread via Cutwail, one of the world’s largest and most notorious spam botnets (for more on Cutwail and its origins and authors, see this post). These junk emails typically spoof trusted brands, including shipping and phone companies, online retailers, social networking sites and financial institutions. The email lures bearing Gameover often come in the form of an invoice, an order confirmation, or a warning about an unpaid bill (usually with a large balance due to increase the likelihood that a victim will click the link). The links in the email have been replaced with those of compromised sites that will silently probe the visitor’s browser for outdated plugins that can be leveraged to install malware.

It will be interesting to hear how the authorities and security researchers involved in this effort managed to gain control over the Gameover botnet, which uses an advanced peer-to-peer (P2P) mechanism to control and update the bot-infected systems. Continue reading →