How 1-Time Passcodes Became a Corporate Liability

Phishers are enjoying remarkable success using text messages to steal remote access credentials and one-time passcodes from employees at some of the world’s largest technology companies and customer support firms. A recent spate of SMS phishing attacks from one cybercriminal group has spawned a flurry of breach disclosures from affected companies, which are all struggling to combat the same lingering security threat: The ability of scammers to interact directly with employees through their mobile devices.

In mid-June 2022, a flood of SMS phishing messages began targeting employees at commercial staffing firms that provide customer support and outsourcing to thousands of companies. The missives asked users to click a link and log in at a phishing page that mimicked their employer’s Okta authentication page. Those who submitted credentials were then prompted to provide the one-time password needed for multi-factor authentication.

The phishers behind this scheme used newly-registered domains that often included the name of the target company, and sent text messages urging employees to click on links to these domains to view information about a pending change in their work schedule.

The phishing sites leveraged a Telegram instant message bot to forward any submitted credentials in real-time, allowing the attackers to use the phished username, password and one-time code to log in as that employee at the real employer website. But because of the way the bot was configured, it was possible for security researchers to capture the information being sent by victims to the public Telegram server.

This data trove was first reported by security researchers at Singapore-based Group-IB, which dubbed the campaign “0ktapus” for the attackers targeting organizations using identity management tools from Okta.com.

“This case is of interest because despite using low-skill methods it was able to compromise a large number of well-known organizations,” Group-IB wrote. “Furthermore, once the attackers compromised an organization they were quickly able to pivot and launch subsequent supply chain attacks, indicating that the attack was planned carefully in advance.”

It’s not clear how many of these phishing text messages were sent out, but the Telegram bot data reviewed by KrebsOnSecurity shows they generated nearly 10,000 replies over approximately two months of sporadic SMS phishing attacks targeting more than a hundred companies.

A great many responses came from those who were apparently wise to the scheme, as evidenced by the hundreds of hostile replies that included profanity or insults aimed at the phishers: The very first reply recorded in the Telegram bot data came from one such employee, who responded with the username “havefuninjail.”

Still, thousands replied with what appear to be legitimate credentials — many of them including one-time codes needed for multi-factor authentication. On July 20, the attackers turned their sights on internet infrastructure giant Cloudflare.com, and the intercepted credentials show at least three employees fell for the scam.

In a blog post earlier this month, Cloudflare said it detected the account takeovers and that no Cloudflare systems were compromised. Cloudflare said it does not rely on one-time passcodes as a second factor, so there was nothing to provide to the attackers. But Cloudflare said it wanted to call attention to the phishing attacks because they would probably work against most other companies.

“This was a sophisticated attack targeting employees and systems in such a way that we believe most organizations would be likely to be breached,” Cloudflare CEO Matthew Prince wrote. “On July 20, 2022, the Cloudflare Security team received reports of employees receiving legitimate-looking text messages pointing to what appeared to be a Cloudflare Okta login page. The messages began at 2022-07-20 22:50 UTC. Over the course of less than 1 minute, at least 76 employees received text messages on their personal and work phones. Some messages were also sent to the employees family members.”

On three separate occasions, the phishers targeted employees at Twilio.com, a San Francisco based company that provides services for making and receiving text messages and phone calls. It’s unclear how many Twilio employees received the SMS phishes, but the data suggest at least four Twilio employees responded to a spate of SMS phishing attempts on July 27, Aug. 2, and Aug. 7.

On that last date, Twilio disclosed that on Aug. 4 it became aware of unauthorized access to information related to a limited number of Twilio customer accounts through a sophisticated social engineering attack designed to steal employee credentials.

“This broad based attack against our employee base succeeded in fooling some employees into providing their credentials,” Twilio said. “The attackers then used the stolen credentials to gain access to some of our internal systems, where they were able to access certain customer data.”

That “certain customer data” included information on roughly 1,900 users of the secure messaging app Signal, which relied on Twilio to provide phone number verification services. In its disclosure on the incident, Signal said that with their access to Twilio’s internal tools the attackers were able to re-register those users’ phone numbers to another device.

On Aug. 25, food delivery service DoorDash disclosed that a “sophisticated phishing attack” on a third-party vendor allowed attackers to gain access to some of DoorDash’s internal company tools. DoorDash said intruders stole information on a “small percentage” of users that have since been notified. TechCrunch reported last week that the incident was linked to the same phishing campaign that targeted Twilio.

This phishing gang apparently had great success targeting employees of all the major mobile wireless providers, but most especially T-Mobile. Between July 10 and July 16, dozens of T-Mobile employees fell for the phishing messages and provided their remote access credentials.

“Credential theft continues to be an ongoing issue in our industry as wireless providers are constantly battling bad actors that are focused on finding new ways to pursue illegal activities like this,” T-Mobile said in a statement. “Our tools and teams worked as designed to quickly identify and respond to this large-scale smishing attack earlier this year that targeted many companies. We continue to work to prevent these types of attacks and will continue to evolve and improve our approach.”

This same group saw hundreds of responses from employees at some of the largest customer support and staffing firms, including Teleperformanceusa.com, Sitel.com and Sykes.com. Teleperformance did not respond to requests for comment. KrebsOnSecurity did hear from Christopher Knauer, global chief security officer at Sitel Group, the customer support giant that recently acquired Sykes. Knauer said the attacks leveraged newly-registered domains and asked employees to approve upcoming changes to their work schedules.

Knauer said the attackers set up the phishing domains just minutes in advance of spamming links to those domains in phony SMS alerts to targeted employees. He said such tactics largely sidestep automated alerts generated by companies that monitor brand names for signs of new phishing domains being registered.

“They were using the domains as soon as they became available,” Knauer said. “The alerting services don’t often let you know until 24 hours after a domain has been registered.”

On July 28 and again on Aug. 7, several employees at email delivery firm Mailchimp provided their remote access credentials to this phishing group. According to an Aug. 12 blog post, the attackers used their access to Mailchimp employee accounts to steal data from 214 customers involved in cryptocurrency and finance.

On Aug. 15, the hosting company DigitalOcean published a blog post saying it had severed ties with MailChimp after its Mailchimp account was compromised. DigitalOcean said the MailChimp incident resulted in a “very small number” of DigitalOcean customers experiencing attempted compromises of their accounts through password resets.

According to interviews with multiple companies hit by the group, the attackers are mostly interested in stealing access to cryptocurrency, and to companies that manage communications with people interested in cryptocurrency investing. In an Aug. 3 blog post from email and SMS marketing firm Klaviyo.com, the company’s CEO recounted how the phishers gained access to the company’s internal tools, and used that to download information on 38 crypto-related accounts.

The ubiquity of mobile phones became a lifeline for many companies trying to manage their remote employees throughout the Coronavirus pandemic. But these same mobile devices are fast becoming a liability for organizations that use them for phishable forms of multi-factor authentication, such as one-time codes generated by a mobile app or delivered via SMS.

Because as we can see from the success of this phishing group, this type of data extraction is now being massively automated, and employee authentication compromises can quickly lead to security and privacy risks for the employer’s partners or for anyone in their supply chain.

Unfortunately, a great many companies still rely on SMS for employee multi-factor authentication. According to a report this year from Okta, 47 percent of workforce customers deploy SMS and voice factors for multi-factor authentication. That’s down from 53 percent that did so in 2018, Okta found.

Some companies (like Knauer’s Sitel) have taken to requiring that all remote access to internal networks be managed through work-issued laptops and/or mobile devices, which are loaded with custom profiles that can’t be accessed through other devices.

Others are moving away from SMS and one-time code apps and toward requiring employees to use physical FIDO multi-factor authentication devices such as security keys, which can neutralize phishing attacks because any stolen credentials can’t be used unless the phishers also have physical access to the user’s security key or mobile device.

This came in handy for Twitter, which announced last year that it was moving all of its employees to using security keys, and/or biometric authentication via their mobile device. The phishers’ Telegram bot reported that on June 16, 2022, five employees at Twitter gave away their work credentials. In response to questions from KrebsOnSecurity, Twitter confirmed several employees were relieved of their employee usernames and passwords, but that its security key requirement prevented the phishers from abusing that information.

Twitter accelerated its plans to improve employee authentication following the July 2020 security incident, wherein several employees were phished and relieved of credentials for Twitter’s internal tools. In that intrusion, the attackers used Twitter’s tools to hijack accounts for some of the world’s most recognizable public figures, executives and celebrities — forcing those accounts to tweet out links to bitcoin scams.

“Security keys can differentiate legitimate sites from malicious ones and block phishing attempts that SMS 2FA or one-time password (OTP) verification codes would not,” Twitter said in an Oct. 2021 post about the change. “To deploy security keys internally at Twitter, we migrated from a variety of phishable 2FA methods to using security keys as our only supported 2FA method on internal systems.”

Update, 6:02 p.m. ET: Clarified that Cloudflare does not rely on TOTP (one-time multi-factor authentication codes) as a second factor for employee authentication.

When Efforts to Contain a Data Breach Backfire

Earlier this month, the administrator of the cybercrime forum Breached received a cease-and-desist letter from a cybersecurity firm. The missive alleged that an auction on the site for data stolen from 10 million customers of Mexico’s second-largest bank was fake news and harming the bank’s reputation. The administrator responded to this empty threat by purchasing the stolen banking data and leaking it on the forum for everyone to download.

On August 3, 2022, someone using the alias “Holistic-K1ller” posted on Breached a thread selling data allegedly stolen from Grupo Financiero Banorte, Mexico’s second-biggest financial institution by total loans. Holistic-K1ller said the database included the full names, addresses, phone numbers, Mexican tax IDs (RFC), email addresses and balances on more than 10 million citizens.

There was no reason to believe Holistic-K1ller had fabricated their breach claim. This identity has been highly active on Breached and its predecessor RaidForums for more than two years, mostly selling databases from hacked Mexican entities. Last month, they sold customer information on 36 million customers of the Mexican phone company Telcel; in March, they sold 33,000 images of Mexican IDs — with the front picture and a selfie of each citizen. That same month, they also sold data on 1.4 million customers of Mexican lending platform Yotepresto.

But this history was either overlooked or ignored by Group-IB, the Singapore-based cybersecurity firm apparently hired by Banorte to help respond to the data breach.

“The Group-IB team has discovered a resource containing a fraudulent post offering to buy Grupo Financiero Banorte’s leaked databases,” reads a letter the Breach administrator said they received from Group-IB. “We ask you to remove this post containing Banorte data. Thank you for your cooperation and prompt attention to this urgent matter.”

The administrator of Breached is “Pompompurin,” the same individual who alerted this author in November 2021 to a glaring security hole in a U.S. Justice Department website that was used to spoof security alerts from the FBI. In a post to Breached on Aug. 8, Pompompurin said they bought the Banorte database from Holistic-K1ller’s sales thread because Group-IB was sending emails complaining about it.

“They also attempted to submit DMCA’s against the website,” Pompompurin wrote, referring to legal takedown requests under the Digital Millennium Copyright Act. “Make sure to tell Banorte that now they need to worry about the data being leaked instead of just being sold.”

Group-IB CEO Dmitriy Volkov said the company has seen some success in the past asking hackers to remove or take down certain information, but that making such requests is not a typical response for the security firm.

“It is not a common practice to send takedown notifications to such forums demanding that such content be removed,” Volkov said. “But these abuse letters are legally binding, which helps build a foundation for further steps taken by law enforcement agencies. Actions contrary to international rules in the regulated space of the Internet only lead to more severe crimes, which — as we know from the case of Raidforums — are successfully investigated and stopped by law enforcement.”

Banorte did not respond to requests for comment. But in a brief written statement picked up on Twitter, Banorte said there was no breach involving their infrastructure, and the data being sold is old.

“There has been no violation of our platforms and technological infrastructure,” Banorte said. “The set of information referred to is inaccurate and outdated, and does not put our users and customers at risk.”

That statement may be 100 percent true. Still, it is difficult to think of a better example of how not to do breach response. Banorte shrugging off this incident as a nothingburger is baffling: While it is almost certainly true that the bank balance information in the Banorte leak is now out of date, the rest of the information (tax IDs, phone numbers, email addresses) is harder to change.

“Is there one person from our community that think sending cease and desist letter to a hackers forum operator is a good idea?,” asked Ohad Zaidenberg, founder of CTI League, a volunteer emergency response community that emerged in 2020 to help fight COVID-19 related scams. “Who does it? Instead of helping, they pushed the organization from the hill.”

Kurt Seifried, director of IT for the CloudSecurityAlliance, was similarly perplexed by the response to the Banorte breach.

“If the data wasn’t real….did the bank think a cease and desist would result in the listing being removed?” Seifried wondered on Twitter. “I mean, isn’t selling breach data a worse crime usually than slander or libel? What was their thought process?”

A more typical response when a large bank suspects a breach is to approach the seller privately through an intermediary to ascertain if the information is valid and what it might cost to take it off the market. While it may seem odd to expect cybercriminals to make good on their claims to sell stolen data to only one party, removing sold stolen items from inventory is a fairly basic function of virtually all cybercriminal markets today (apart from perhaps sites that traffic in stolen identity data).

At a minimum, negotiating or simply engaging with a data seller can buy the victim organization additional time and clues with which to investigate the claim and ideally notify affected parties of a breach before the stolen data winds up online.

It is true that a large number of hacked databases put up for sale on the cybercrime underground are sold only after a small subset of in-the-know thieves have harvested all of the low-hanging fruit in the data — e.g., access to cryptocurrency accounts or user credentials that are recycled across multiple websites. And it’s certainly not unheard of for cybercriminals to go back on their word and re-sell or leak information that they have sold previously.

But companies in the throes of responding to a data security incident do themselves and customers no favors when they underestimate their adversaries, or try to intimidate cybercrooks with legal threats. Such responses generally accomplish nothing, except unnecessarily upping the stakes for everyone involved while displaying a dangerous naiveté about how the cybercrime underground works.

Update, Aug. 17, 10:32 a.m.: Thanks to a typo by this author, a request for comment sent to Group-IB was not delivered in advance of this story. The copy above has been updated to include a comment from Group-IB’s CEO.

Breach Exposes Users of Microleaves Proxy Service

Microleaves, a ten-year-old proxy service that lets customers route their web traffic through millions of Microsoft Windows computers, recently fixed a vulnerability in their website that exposed their entire user database. Microleaves claims its proxy software is installed with user consent, but data exposed in the breach shows the service has a lengthy history of being supplied with new proxies by affiliates incentivized to distribute the software any which way they can — such as by secretly bundling it with other titles.

Launched in 2013, Microleaves is a service that allows customers to route their Internet traffic through PCs in virtually any country or city around the globe. Microleaves works by changing each customer’s Internet Protocol (IP) address every five to ten minutes.

The service, which accepts PayPal, Bitcoin and all major credit cards, is aimed primarily at enterprises engaged in repetitive, automated activity that often results in an IP address being temporarily blocked — such as data scraping, or mass-creating new accounts at some service online.

In response to a report about the data exposure from KrebsOnSecurity, Microleaves said it was grateful for being notified about a “very serious issue regarding our customer information.”

Abhishek Gupta is the PR and marketing manager for Microleaves, which he said in the process of being rebranded to “Shifter.io.” Gupta said the report qualified as a “medium” severity security issue in Shifter’s brand new bug bounty program (the site makes no mention of a bug bounty), which he said offers up to $2,000 for reporting data exposure issues like the one they just fixed. KrebsOnSecurity declined the offer and requested that Shifter donate the amount to the Electronic Frontier Foundation (EFF), a digital rights group.

From its inception nearly a decade ago, Microleaves has claimed to lease between 20-30 million IPs via its service at any time. Riley Kilmer, co-founder of the proxy-tracking service Spur.us, said that 20-30 million number might be accurate for Shifter if measured across a six-month time frame. Currently, Spur is tracking roughly a quarter-million proxies associated with Microleaves/Shifter each day, with a high rate of churn in IPs.

Early on, this rather large volume of IP addresses led many to speculate that Microleaves was just a botnet which was being resold as a commercial proxy service.

The very first discussion thread started by the new user Microleaves on the forum BlackHatWorld in 2013 sought forum members who could help test and grow the proxy network. At the time, the Microleaves user said their proxy network had 150,000 IPs globally, and was growing quickly.

One of BlackHatWorld’s moderators asked the administrator of the forum to review the Microleaves post.

“User states has 150k proxies,” the forum skeptic wrote. “No seller on BHW has 150k working daily proxies none of us do. Which hints at a possible BOTNET. That’s the only way you will get 150k.”

Microleaves has long been classified by antivirus companies as adware or as a “potentially unwanted program” (PUP), the euphemism that antivirus companies use to describe executable files that get installed with ambiguous consent at best, and are often part of a bundle of software tied to some “free” download. Security vendor Kaspersky flags the Microleaves family of software as a trojan horse program that commandeers the user’s Internet connection as a proxy without notifying the user.

“While working, these Trojans pose as Microsoft Windows Update,” Kaspersky wrote.

In a February 2014 post to BlackHatWorld, Microleaves announced that its sister service — reverseproxies[.]com — was now offering an “Auto CAPTCHA Solving Service,” which automates the solving of those squiggly and sometimes frustrating puzzles that many websites use to distinguish bots from real visitors. The CAPTCHA service was offered as an add-on to the Microleaves proxy service, and ranged in price from $20 for a 2-day trial to $320 for solving up to 80 captchas simultaneously.

“We break normal Recaptcha with 60-90% success rate, recaptcha with blobs 30% success, and 500+ other captcha,” Microleaves wrote. “As you know all success rate on recaptcha depends very much on good proxies that are fresh and not spammed!”

WHO IS ACIDUT?

The exposed Microleaves user database shows that the first user created on the service — username “admin” — used the email address alex.iulian@aol.com. A search on that email address in Constella Intelligence, a service that tracks breached data, reveals it was used to create an account at the link shortening service bit.ly under the name Alexandru Florea, and the username “Acidut.” [Full disclosure: Constella is currently an advertiser on this website].

According to the cyber intelligence company Intel 471, a user named Acidut with the email address iulyan87_4u@gmail.com had an active presence on almost a dozen shadowy money-making and cybercrime forums from 2010 to 2017, including BlackHatWorld, Carder[.]pro, Hackforums, OpenSC, and CPAElites.

In a 2011 post on Hackforums, Acidut said they were building a botnet using an “exploit kit,” a set of browser exploits made to be stitched into hacked websites and foist malware on visitors. Acidut claimed their exploit kit was generating 3,000 to 5,000 new bots each day. OpenSC was hacked at one point, and its private messages show Acidut purchased a license from Exmanoize, the handle used by the creator of the Eleonore Exploit Kit.

By November 2013, Acidut was advertising the sale of “26 million SOCKS residential proxies.” In a March 2016 post to CPAElites, Acidut said they had a worthwhile offer for people involved in pay-per-install or “PPI” schemes, which match criminal gangs who pay for malware installs with enterprising hackers looking to sell access to compromised PCs and websites.

Because pay-per-install affiliate schemes rarely impose restrictions on how the software can be installed, such programs can be appealing for cybercriminals who already control large collections of hacked machines and/or compromised websites. Indeed, Acidut went a step further, adding that their program could be quietly and invisibly nested inside of other programs.

“For those of you who are doing PPI I have a global offer that you can bundle to your installer,” Acidut wrote. “I am looking for many installs for an app that will generate website visits. The installer has a silence version which you can use inside your installer. I am looking to buy as many daily installs as possible worldwide, except China.”

Asked about the source of their proxies in 2014, the Microleaves user responded that it was “something related to a PPI network. I can’t say more and I won’t get into details.”

Acidut authored a similar message on the forum BlackHatWorld in 2013, where they encouraged users to contact them on Skype at the username “nevo.julian.” That same Skype contact address was listed prominently on the Microleaves homepage up until about a week ago when KrebsOnSecurity first reached out to the company.

ONLINE[.]IO (NOW MERCIFULLY OFFLINE)

There is a Facebook profile for an Alexandru Iulian Florea from Constanta, Romania, whose username on the social media network is Acidut. Prior to KrebsOnSecurity alerting Shifter of its data breach, the Acidut profile page associated Florea with the websites microleaves.com, shrooms.io, leftclick[.]io, and online[.]io. Mr. Florea did not respond to multiple requests for comment, and his Facebook page no longer mentions these domains.

Leftclick and online[.]io emerged as subsidiaries of Microleaves between 2017 and 2018. According to a help wanted ad posted in 2018 for a developer position at online[.]io, the company’s services were brazenly pitched to investors as “a cybersecurity and privacy tool kit, offering extensive protection using advanced adblocking, anti-tracking systems, malware protection, and revolutionary VPN access based on residential IPs.”

“Online[.]io is developing the first fully decentralized peer-to-peer networking technology and revolutionizing the browsing experience by making it faster, ad free, more reliable, secure and non-trackable, thus freeing the Internet from annoying ads, malware, and trackers,” reads the rest of that help wanted ad.

Microleaves CEO Alexandru Florea gave an “interview” to the website Irishtechnews.ie in 2018, in which he explained how Online[.]io (OIO) was going to upend the online advertising and security industries with its initial coin offering (ICO). The word interview is in air quotes because the following statements by Florea deserved some serious pushback by the interviewer.

“Online[.]io solution, developed using the Ethereum blockchain, aims at disrupting the digital advertising market valued at more than $1 trillion USD,” Alexandru enthused. “By staking OIO tokens and implementing our solution, the website operators will be able to access a new non-invasive revenue stream, which capitalizes on time spent by users online.”

“At the same time, internet users who stake OIO tokens will have the opportunity to monetize on the time spent online by themselves and their peers on the World Wide Web,” he continued. “The time spent by users online will lead to ICE tokens being mined, which in turn can be used in the dedicated merchant system or traded on exchanges and consequently changed to fiat.”

Translation: If you install our proxy bot/CAPTCHA-solver/ad software on your computer — or as an exploit kit on your website — we’ll make millions hijacking ads and you will be rewarded with heaps of soon-to-be-worthless shitcoin. Oh, and all your security woes will disappear, too.

It’s unclear how many Internet users and websites willingly agreed to get bombarded with Online[.]io’s annoying ads and search hijackers — and to have their PC turned into a proxy or CAPTCHA-solving zombie for others. But that is exactly what multiple security companies said happened when users encountered online[.]io, which operated using the Microsoft Windows process name of “online-guardian.exe.”

Incredibly, Crunchbase says Online[.]io raised $6 million in funding for an initial coin offering in 2018, based on the plainly ludicrous claims made above. Since then, however, online[.]io seems to have gone…offline, for good.

SUPER TECH VENTURES?

Until this week, Shifter.io’s website also exposed information about its customer base and most active users, as well as how much money each client has paid over the lifetime of their subscription. The data indicates Shifter has earned more than $11.7 million in direct payments, although it’s unclear how far back in time those payment records go, or how complete they are.

The bulk of Shifter customers who spent more than $100,000 at the proxy service appear to be digital advertising companies, including some located in the United States. None of the several Shifter customers approached by KrebsOnSecurity agreed to be interviewed.

Shifter’s Gupta said he’d been with the company for three years, since the new owner took over the company and made the rebrand to Shifter.

“The company has been on the market for a long time, but operated under a different brand called Microleaves, until new ownership and management took over the company started a reorganization process that is still on-going,” Gupta said. “We are fully transparent. Mostly [our customers] work in the data scraping niche, this is why we actually developed more products in this zone and made a big shift towards APIs and integrated solutions in the past year.”

Ah yes, the same APIs and integrated solutions that were found exposed to the Internet and leaking all of Shifter’s customer information.

Gupta said the original founder of Microleaves was a man from India, who later sold the business to Florea. According to Gupta, the Romanian entrepreneur had multiple issues in trying to run the company, and then sold it three years ago to the current owner — Super Tech Ventures, a private equity company based in Taiwan.

“Our CEO is Wang Wei, he has been with the company since 3 years ago,” Gupta said. “Mr. Florea left the company two years ago after ending this transition period.”

Google and other search engines seem to know nothing about a Super Tech Ventures based in Taiwan. Incredibly, Shifter’s own PR person claimed that he, too, was in the dark on this subject.

“I would love to help, but I really don’t know much about the mother company,” Gupta said, essentially walking back his “fully transparent” statement. “I know they are a branch of the bigger group of asian investment firms focused on private equity in multiple industries.”

Adware and proxy software are often bundled together with “free” software utilities online, or with popular software titles that have been pirated and quietly fused with installers tied to various PPI affiliate schemes.

But just as often, these intrusive programs will include some type of notice — even if installed as part of a software bundle — that many users simply do not read and click “Next” to get on with installing whatever software they’re seeking to use. In these cases, selecting the “basic” or “default” settings while installing usually hides any per-program installation prompts, and assumes you agree to all of the bundled programs being installed. It’s always best to opt for the “custom” installation mode, which can give you a better idea of what is actually being installed, and can let you control certain aspects of the installation.

Either way, it’s best to start with the assumption that if a software or service online is “free,” that there is likely some component involved that allows the provider of that service to monetize your activity. As KrebsOnSecurity noted at the conclusion of last week’s story on a China-based proxy service called 911, the rule of thumb for transacting online is that if you’re not the paying customer, then you and/or your devices are probably the product that’s being sold to others.

Further reading on proxy services:

July 18, 2022: A Deep Dive Into the Residential Proxy Service ‘911’
June 28, 2022: The Link Between AWM Proxy & the Glupteba Botnet
June 22, 2022: Meet the Administrators of the RSOCKS Proxy Botnet
Sept. 1, 2021: 15-Year-Old Malware Proxy Network VIP72 Goes Dark
Aug. 19, 2019: The Rise of “Bulletproof” Residential Networks

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.