Why Your Wi-Fi Router Doubles as an Apple AirTag

Apple and the satellite-based broadband service Starlink each recently took steps to address new research into the potential security and privacy implications of how their services geo-locate devices. Researchers from the University of Maryland say they relied on publicly available data from Apple to track the location of billions of devices globally — including non-Apple devices like Starlink systems — and found they could use this data to monitor the destruction of Gaza, as well as the movements and in many cases identities of Russian and Ukrainian troops.

At issue is the way that Apple collects and publicly shares information about the precise location of all Wi-Fi access points seen by its devices. Apple collects this location data to give Apple devices a crowdsourced, low-power alternative to constantly requesting global positioning system (GPS) coordinates.

Both Apple and Google operate their own Wi-Fi-based Positioning Systems (WPS) that obtain certain hardware identifiers from all wireless access points that come within range of their mobile devices. Both record the Media Access Control (MAC) address that a Wi-FI access point uses, known as a Basic Service Set Identifier or BSSID.

Periodically, Apple and Google mobile devices will forward their locations — by querying GPS and/or by using cellular towers as landmarks — along with any nearby BSSIDs. This combination of data allows Apple and Google devices to figure out where they are within a few feet or meters, and it’s what allows your mobile phone to continue displaying your planned route even when the device can’t get a fix on GPS.

With Google’s WPS, a wireless device submits a list of nearby Wi-Fi access point BSSIDs and their signal strengths — via an application programming interface (API) request to Google — whose WPS responds with the device’s computed position. Google’s WPS requires at least two BSSIDs to calculate a device’s approximate position.

Apple’s WPS also accepts a list of nearby BSSIDs, but instead of computing the device’s location based off the set of observed access points and their received signal strengths and then reporting that result to the user, Apple’s API will return the geolocations of up to 400 hundred more BSSIDs that are nearby the one requested. It then uses approximately eight of those BSSIDs to work out the user’s location based on known landmarks.

In essence, Google’s WPS computes the user’s location and shares it with the device. Apple’s WPS gives its devices a large enough amount of data about the location of known access points in the area that the devices can do that estimation on their own.

That’s according to two researchers at the University of Maryland, who theorized they could use the verbosity of Apple’s API to map the movement of individual devices into and out of virtually any defined area of the world. The UMD pair said they spent a month early in their research continuously querying the API, asking it for the location of more than a billion BSSIDs generated at random.

They learned that while only about three million of those randomly generated BSSIDs were known to Apple’s Wi-Fi geolocation API, Apple also returned an additional 488 million BSSID locations already stored in its WPS from other lookups.

UMD Associate Professor David Levin and Ph.D student Erik Rye found they could mostly avoid requesting unallocated BSSIDs by consulting the list of BSSID ranges assigned to specific device manufacturers. That list is maintained by the Institute of Electrical and Electronics Engineers (IEEE), which is also sponsoring the privacy and security conference where Rye is slated to present the UMD research later today.

Plotting the locations returned by Apple’s WPS between November 2022 and November 2023, Levin and Rye saw they had a near global view of the locations tied to more than two billion Wi-Fi access points. The map showed geolocated access points in nearly every corner of the globe, apart from almost the entirety of China, vast stretches of desert wilderness in central Australia and Africa, and deep in the rainforests of South America.

The researchers said that by zeroing in on or “geofencing” other smaller regions indexed by Apple’s location API, they could monitor how Wi-Fi access points moved over time. Why might that be a big deal? They found that by geofencing active conflict zones in Ukraine, they were able to determine the location and movement of Starlink devices used by both Ukrainian and Russian forces.

The reason they were able to do that is that each Starlink terminal — the dish and associated hardware that allows a Starlink customer to receive Internet service from a constellation of orbiting Starlink satellites — includes its own Wi-Fi access point, whose location is going to be automatically indexed by any nearby Apple devices that have location services enabled.

The University of Maryland team geo-fenced various conflict zones in Ukraine, and identified at least 3,722 Starlink terminals geolocated in Ukraine.

“We find what appear to be personal devices being brought by military personnel into war zones, exposing pre-deployment sites and military positions,” the researchers wrote. “Our results also show individuals who have left Ukraine to a wide range of countries, validating public reports of where Ukrainian refugees have resettled.”

In an interview with KrebsOnSecurity, the UMD team said they found that in addition to exposing Russian troop pre-deployment sites, the location data made it easy to see where devices in contested regions originated from.

“This includes residential addresses throughout the world,” Levin said. “We even believe we can identify people who have joined the Ukraine Foreign Legion.”

Levin and Rye said they shared their findings with Starlink in March 2024, and that Starlink told them the company began shipping software updates in 2023 that force Starlink access points to randomize their BSSIDs.

Starlink’s parent SpaceX did not respond to requests for comment. But the researchers shared a graphic they said was created from their Starlink BSSID monitoring data, which shows that just in the past month there was a substantial drop in the number of Starlink devices that were geo-locatable using Apple’s API.

They also shared a written statement they received from Starlink, which acknowledged that Starlink User Terminal routers originally used a static BSSID/MAC:

“In early 2023 a software update was released that randomized the main router BSSID. Subsequent software releases have included randomization of the BSSID of WiFi repeaters associated with the main router. Software updates that include the repeater randomization functionality are currently being deployed fleet-wide on a region-by-region basis. We believe the data outlined in your paper is based on Starlink main routers and or repeaters that were queried prior to receiving these randomization updates.”

The researchers also focused their geofencing on the Israel-Hamas war in Gaza, and were able to track the migration and disappearance of devices throughout the Gaza Strip as Israeli forces cut power to the country and bombing campaigns knocked out key infrastructure.

“As time progressed, the number of Gazan BSSIDs that are geolocatable continued to decline,” they wrote. “By the end of the month, only 28% of the original BSSIDs were still found in the Apple WPS.”

In late March 2024, Apple quietly updated its website to note that anyone can opt out of having the location of their wireless access points collected and shared by Apple — by appending “_nomap” to the end of the Wi-Fi access point’s name (SSID). Adding “_nomap” to your Wi-Fi network name also blocks Google from indexing its location.

Asked about the changes, Apple said they have respected the “_nomap” flag on SSIDs for some time, but that this was only called out in a support article earlier this year.

Rye said Apple’s response addressed the most depressing aspect of their research: That there was previously no way for anyone to opt out of this data collection.

“You may not have Apple products, but if you have an access point and someone near you owns an Apple device, your BSSID will be in [Apple’s] database,” he said. “What’s important to note here is that every access point is being tracked, without opting in, whether they run an Apple device or not. Only after we disclosed this to Apple have they added the ability for people to opt out.”

The researchers said they hope Apple will consider additional safeguards, such as proactive ways to limit abuses of its location API.

“It’s a good first step,” Levin said of Apple’s privacy update in March. “But this data represents a really serious privacy vulnerability. I would hope Apple would put further restrictions on the use of its API, like rate-limiting these queries to keep people from accumulating massive amounts of data like we did.”

The UMD researchers said they omitted certain details from their study to protect the users they were able to track, noting that the methods they used could present risks for those fleeing abusive relationships or stalkers.

“We observe routers move between cities and countries, potentially representing their owner’s relocation or a business transaction between an old and new owner,” they wrote. “While there is not necessarily a 1-to-1 relationship between Wi-Fi routers and users, home routers typically only have several. If these users are vulnerable populations, such as those fleeing intimate partner violence or a stalker, their router simply being online can disclose their new location.”

The researchers said Wi-Fi access points that can be created using a mobile device’s built-in cellular modem do not create a location privacy risk for their users because mobile phone hotspots will choose a random BSSID when activated.

“Modern Android and iOS devices will choose a random BSSID when you go into hotspot mode,” he said. “Hotspots are already implementing the strongest recommendations for privacy protections. It’s other types of devices that don’t do that.”

For example, they discovered that certain commonly used travel routers compound the potential privacy risks.

“Because travel routers are frequently used on campers or boats, we see a significant number of them move between campgrounds, RV parks, and marinas,” the UMD duo wrote. “They are used by vacationers who move between residential dwellings and hotels. We have evidence of their use by military members as they deploy from their homes and bases to war zones.”

A copy of the UMD research is available here (PDF).

Update, May 22, 4:54 p.m. ET: Added response from Apple.

Re-Victimization from Police-Auctioned Cell Phones

Countless smartphones seized in arrests and searches by police forces across the United States are being auctioned online without first having the data on them erased, a practice that can lead to crime victims being re-victimized, a new study found. In response, the largest online marketplace for items seized in U.S. law enforcement investigations says it now ensures that all phones sold through its platform will be data-wiped prior to auction.

Researchers at the University of Maryland last year purchased 228 smartphones sold “as-is” from PropertyRoom.com, which bills itself as the largest auction house for police departments in the United States. Of phones they won at auction (at an average of $18 per phone), the researchers found 49 had no PIN or passcode; they were able to guess an additional 11 of the PINs by using the top-40 most popular PIN or swipe patterns.

Phones may end up in police custody for any number of reasons — such as its owner was involved in identity theft — and in these cases the phone itself was used as a tool to commit the crime.

“We initially expected that police would never auction these phones, as they would enable the buyer to recommit the same crimes as the previous owner,” the researchers explained in a paper released this month. “Unfortunately, that expectation has proven false in practice.”

The researchers said while they could have employed more aggressive technological measures to work out more of the PINs for the remaining phones they bought, they concluded based on the sample that a great many of the devices they won at auction had probably not been data-wiped and were protected only by a PIN.

Beyond what you would expect from unwiped second hand phones — every text message, picture, email, browser history, location history, etc. — the 61 phones they were able to access also contained significant amounts of data pertaining to crime — including victims’ data — the researchers found.

Some readers may be wondering at this point, “Why should we care about what happens to a criminal’s phone?” First off, it’s not entirely clear how these phones ended up for sale on PropertyRoom.

“Some folks are like, ‘Yeah, whatever, these are criminal phones,’ but are they?” said Dave Levin, an assistant professor of computer science at University of Maryland.

“We started looking at state laws around what they’re supposed to do with lost or stolen property, and we found that most of it ends up going the same route as civil asset forfeiture,” Levin continued. “Meaning, if they can’t find out who owns something, it eventually becomes the property of the state and gets shipped out to these resellers.”

Also, the researchers found that many of the phones clearly had personal information on them regarding previous or intended targets of crime: A dozen of the phones had photographs of government-issued IDs. Three of those were on phones that apparently belonged to sex workers; their phones contained communications with clients.

One phone had full credit files for eight different people on it. On another device they found a screenshot including 11 stolen credit cards that were apparently purchased from an online carding shop. On yet another, the former owner had apparently been active in a Telegram group chat that sold tutorials on how to run identity theft scams.

The most interesting phone from the batches they bought at auction was one with a sticky note attached that included the device’s PIN and the notation “Gry Keyed,” no doubt a reference to the Graykey software that is often used by law enforcement agencies to brute-force a mobile device PIN.

“That one had the PIN on the back,” Levin said. “The message chain on that phone had 24 Experian and TransUnion credit histories”.

The University of Maryland team said they took care in their research not to further the victimization of people whose information was on the devices they purchased from PropertyRoom.com. That involved ensuring that none of the devices could connect to the Internet when powered on, and scanning all images on the devices against known hashes for child sexual abuse material.

It is common to find phones and other electronics for sale on auction platforms like eBay that have not been wiped of sensitive data, but in those cases eBay doesn’t possess the items being sold. In contrast, platforms like PropertyRoom obtain devices and resell them at auction directly.

PropertyRoom did not respond to multiple requests for comment. But the researchers said sometime in the past few months PropertyRoom began posting a notice stating that all mobile devices would be wiped of their data before being sold at auction.

“We informed them of our research in October 2022, and they responded that they would review our findings internally,” Levin said. “They stopped selling them for a while, but then it slowly came back, and then we made sure we won every auction. And all of the ones we got from that were indeed wiped, except there were four devices that had external SD [storage] cards in them that weren’t wiped.”

A copy of the University of Maryland study is here (PDF).

Feds Take Down 13 More DDoS-for-Hire Services

The U.S. Federal Bureau of Investigation (FBI) this week seized 13 domain names connected to “booter” services that let paying customers launch crippling distributed denial-of-service (DDoS) attacks. Ten of the domains are reincarnations of DDoS-for-hire services the FBI seized in December 2022, when it charged six U.S. men with computer crimes for allegedly operating booters.

Booter services are advertised through a variety of methods, including Dark Web forums, chat platforms and even youtube.com. They accept payment via PayPal, Google Wallet, and/or cryptocurrencies, and subscriptions can range in price from just a few dollars to several hundred per month. The services are generally priced according to the volume of traffic to be hurled at the target, the duration of each attack, and the number of concurrent attacks allowed.

The websites that saw their homepages replaced with seizure notices from the FBI this week include booter services like cyberstress[.]org and exoticbooter[.]com, which the feds say were used to launch millions of attacks against millions of victims.

“School districts, universities, financial institutions and government websites are among the victims who have been targeted in attacks launched by booter services,” federal prosecutors in Los Angeles said in a statement.

Purveyors of booters or “stressers” claim they are not responsible for how customers use their services, and that they aren’t breaking the law because — like most security tools — these services can be used for good or bad purposes. Most booter sites employ wordy “terms of use” agreements that require customers to agree they will only stress-test their own networks — and that they won’t use the service to attack others.

But the DOJ says these disclaimers usually ignore the fact that most booter services are heavily reliant on constantly scanning the Internet to commandeer misconfigured devices that are critical for maximizing the size and impact of DDoS attacks. What’s more, none of the services seized by the government required users to demonstrate that they own the Internet addresses being stress-tested, something a legitimate testing service would insist upon.

This is the third in a series of U.S. and international law enforcement actions targeting booter services. In December 2022, the feds seized four-dozen booter domains and charged six U.S. men with computer crimes related to their alleged ownership of the popular DDoS-for-hire services. In December 2018, the feds targeted 15 booter sites, and three booter store defendants who later pleaded guilty.

While the FBI’s repeated seizing of booter domains may seem like an endless game of virtual Whac-a-Mole, continuously taking these services offline imposes high enough costs for the operators that some of them will quit the business altogether, says Richard Clayton, director of Cambridge University’s Cybercrime Centre.

In 2020, Clayton and others published “Cybercrime is Mostly Boring,” an academic study on the quality and types of work needed to build, maintain and defend illicit enterprises that make up a large portion of the cybercrime-as-a-service market. The study found that operating a booter service effectively requires a mind-numbing amount of constant, tedious work that tends to produce high burnout rates for booter service operators — even when the service is operating efficiently and profitably.

For example, running an effective booter service requires a substantial amount of administrative work and maintenance, much of which involves constantly scanning for, commandeering and managing large collections of remote systems that can be used to amplify online attacks, Clayton said. On top of that, building brand recognition and customer loyalty takes time.

“If you’re running a booter and someone keeps taking your domain or hosting away, you have to then go through doing the same boring work all over again,” Clayton told KrebsOnSecurity. “One of the guys the FBI arrested in December [2022] spent six months moaning that he lost his servers, and could people please lend him some money to get it started again.”

In a statement released Wednesday, prosecutors in Los Angeles said four of the six men charged last year for running booter services have since pleaded guilty. However, at least one of the defendants from the 2022 booter bust-up — John M. Dobbs, 32, of Honolulu, HI — has pleaded not guilty and is signaling he intends to take his case to trial.

Dobbs is a computer science graduate student who for the past decade openly ran IPStresser[.]com, a popular and powerful attack-for-hire service that he registered with the state of Hawaii using his real name and address. Likewise, the domain was registered in Dobbs’s name and hometown in Pennsylvania. Prosecutors say Dobbs’ service attracted more than two million registered users, and was responsible for launching a staggering 30 million distinct DDoS attacks.

Many accused stresser site operators have pleaded guilty over the years after being hit with federal criminal charges. But the government’s core claim — that operating a booter site is a violation of U.S. computer crime laws — wasn’t properly tested in the courts until September 2021.

That was when a jury handed down a guilty verdict against Matthew Gatrel, a then 32-year-old St. Charles, Ill. man charged in the government’s first 2018 mass booter bust-up. Despite admitting to FBI agents that he ran two booter services (and turning over plenty of incriminating evidence in the process), Gatrel opted to take his case to trial, defended the entire time by court-appointed attorneys.

Gatrel was convicted on all three charges of violating the Computer Fraud and Abuse Act, including conspiracy to commit unauthorized impairment of a protected computer, conspiracy to commit wire fraud, and unauthorized impairment of a protected computer. He was sentenced to two years in prison.

A copy of the FBI’s booter seizure warrant is here (PDF). According to the DOJ, the defendants who pleaded guilty to operating booter sites include:

–Jeremiah Sam Evans Miller, aka “John The Dev,” 23, of San Antonio, Texas, who pleaded guilty on April 6 to conspiracy and violating the computer fraud and abuse act related to the operation of a booter service named RoyalStresser[.]com (formerly known as Supremesecurityteam[.]com);

–Angel Manuel Colon Jr., aka “Anonghost720” and “Anonghost1337,” 37, of Belleview, Florida, who pleaded guilty on February 13 to conspiracy and violating the computer fraud and abuse act related to the operation of a booter service named SecurityTeam[.]io;

–Shamar Shattock, 19, of Margate, Florida, who pleaded guilty on March 22 to conspiracy to violate the computer fraud and abuse act related to the operation of a booter service known as Astrostress[.]com;

–Cory Anthony Palmer, 23, of Lauderhill, Florida, who pleaded guilty on February 16 to conspiracy to violate the computer fraud and abuse act related to the operation of a booter service known as Booter[.]sx.

All four defendants are scheduled to be sentenced this summer.

The booter domains seized by the FBI this week include:

cyberstress[.]org
exoticbooter[.]com
layerstress[.]net
orbitalstress[.]xyz
redstresser[.]io
silentstress[.]wtf
sunstresser[.]net
silent[.]to
mythicalstress[.]net
dreams-stresser[.]org
stresserbest[.]io
stresserus[.]io
quantum-stress[.]org

A Deep Dive Into the Residential Proxy Service ‘911’

For the past seven years, an online service known as 911 has sold access to hundreds of thousands of Microsoft Windows computers daily, allowing customers to route their Internet traffic through PCs in virtually any country or city around the globe — but predominantly in the United States. 911 says its network is made up entirely of users who voluntarily install its “free VPN” software. But new research shows the proxy service has a long history of purchasing installations via shady “pay-per-install” affiliate marketing schemes, some of which 911 operated on its own.

911[.]re is one of the original “residential proxy” networks, which allow someone to rent a residential IP address to use as a relay for his/her Internet communications, providing anonymity and the advantage of being perceived as a residential user surfing the web.

From a website’s perspective, the IP traffic of a residential proxy network user appears to originate from the rented residential IP address, not from the proxy service customer. These services can be used in a legitimate manner for several business purposes — such as price comparisons or sales intelligence — but they are massively abused for hiding cybercrime activity because they can make it difficult to trace malicious traffic to its original source.

Residential proxy services are often marketed to people seeking the ability to evade country-specific blocking by the major movie and media streaming providers. But some of them — like 911 — build their networks in part by offering “free VPN” or “free proxy” services that are powered by software which turns the user’s PC into a traffic relay for other users. In this scenario, users indeed get to use a free VPN service, but they are often unaware that doing so will turn their computer into a proxy that lets others use their Internet address to transact online.

Researchers at the University of Sherbrooke in Canada recently published an analysis of 911, and found there were roughly 120,000 PCs for rent via the service, with the largest number of them located in the United States.

“The 911[.]re network uses at least two free VPN services to lure its users to install a malware-like software that achieves persistence on the user’s computer,” the researchers wrote. “During the research we identified two free VPN services that [use] a subterfuge to lure users to install software that looks legitimate but makes them part of the network. These two software are currently unknown to most if not all antivirus companies.”

The researchers concluded that 911 is supported by a “mid scale botnet-like infrastructure that operates in several networks, such as corporate, government and critical infrastructure.” The Canadian team said they found many of the 911 nodes available for rent were situated within several major US-based universities and colleges, critical infrastructures such as clean water, defense contractors, law enforcement and government networks.

Highlighting the risk that 911 nodes could pose to internal corporate networks, they observed that “the infection of a node enables the 911.re user to access shared resources on the network such as local intranet portals or other services.”

“It also enables the end user to probe the LAN network of the infected node,” the paper continues. “Using the internal router, it would be possible to poison the DNS cache of the LAN router of the infected node, enabling further attacks.”

THE INTERNET NEVER FORGETS

A review of the clues left behind by 911’s early days on the Internet paint a more complete picture of this long-running proxy network. The domain names used by 911 over the years have a few common elements in their original WHOIS registration records, including the address ustraffic@qq.com and a Yunhe Wang from Beijing.

That ustraffic email is tied to a small number of interesting domains, including browsingguard[.]com, cleantraffic[.]net, execlean[.]net, proxygate[.]net, and flashupdate[.]net.

A cached copy of flashupdate[.]net available at the Wayback Machine shows that in 2016 this domain was used for the “ExE Bucks” affiliate program, a pay-per-install business which catered to people already running large collections of hacked computers or compromised websites. Affiliates were paid a set amount for each installation of the software, with higher commissions for installs in more desirable nations, particularly Europe, Canada and the United States.

“We load only one software — it’s a Socks5 proxy program,” read the message to ExE Bucks affiliates. The website said affiliates were free to spread the proxy software by any means available (i.e. “all promotion methods allowed”). The website’s copyright suggests the ExE Bucks affiliate program dates back to 2012.

Another domain tied to the ustraffic@qq.com email in 2016 was ExeClean[.]net, a service that advertised to cybercriminals seeking to obfuscate their malicious software so that it goes undetected by all or at least most of the major antivirus products on the market.

“Our technology ensures the maximum security from reverse engineering and antivirus detections,” ExEClean promised.

Yet another domain connected to the ustraffic email is p2pshare[.]net, which advertised “free unlimited internet file-sharing platform” for those who agreed to install their software.

Still more domains associated with ustraffic@qq.com suggest 911’s proxy has been disguised as security updates for video player plugins, including flashplayerupdate[.]xyz, mediaplayerupdate[.]xyz, and videoplayerupdate[.]xyz.

The earliest version of the 911 website available from the Wayback Machine is from 2016. A sister service called proxygate[.]net launched roughly a year prior to 911 as a “free” public test of the budding new residential proxy service. “Basically using clients to route for everyone,” was how Proxygate described itself in 2016.

For more than a year after its founding, the 911 website was written entirely in Simplified Chinese. The service has only ever accepted payment via virtual currencies such as Bitcoin and Monero, as well as Alipay and China UnionPay, both payment platforms based in China.

Initially, the terms and conditions of 911’s “End User License Agreement (EULA) named a company called Wugaa Enterprises LLC, which was registered in California in 2016. Records from the California Secretary of State office show that in November 2016, Wugaa Enterprises said it was in the Internet advertising business, and had named as its CEO as one Nicolae Aurelian Mazgarean of Brasov, Romania.

A search of European VAT numbers shows the same Brasov, RO address tied to an enterprise called PPC Leads SRL (in the context of affiliate-based marketing, “PPC” generally refers to the term “pay-per-click”).

911’s EULA would later change its company name and address in 2017, to International Media Ltd. in the British Virgin Islands. That is the same information currently displayed on the 911 website.

The EULA attached to 911 software downloaded from browsingguard[.]com (tied to the same ustraffic@qq email that registered 911) references a company called Gold Click Limited. According to the UK Companies House, Gold Click Limited was registered in 2016 to a 34-year-old Yunhe Wang from Beijing City. Many of the WHOIS records for the above mentioned domains also include the name Yunhe Wang, or some variation thereof.

In a response to questions from KrebsOnSecurity, 911 said the researchers were wrong, and that 911 has nothing to do with any of the other domains mentioned above.

“We have 911 SDK link and how it works described clearly in the “Terms of use” of affiliated partners products, and we have details of how the community powered network works on our webpages,” read an email response.

“Besides that, for protecting the end users, we banned many domains’ access and blocked the vulnerable ports, e.g. spamming emails, and torrent is not possible from the 911 network,” the reply continued. “Same as scanning and many others…Accessing to the Lan network and router is also blocked. We are monitoring 911 user’s account closely, once any abnormal behavior detected, we suspend the user’s account right away.”

FORUM ACTIVITY?

911 has remained one of the most popular services among denizens of the cybercrime underground for years, becoming almost shorthand for connecting to that “last mile” of cybercrime. Namely, the ability to route one’s malicious traffic through a computer that is geographically close to the consumer whose credit card they’re about to charge at some website, or whose bank account they’re about to empty.

Given the frequency with which 911 has been praised by cybercrooks on the top forums, it was odd to find the proprietors of 911 do not appear to have created any official support account for the service on any of several dozen forums reviewed by this author going back a decade. However there are two cybercriminal identities on the forums that have responded to individual 911 help requests, and who promoted the sale of 911 accounts via their handles.

Both of these identities were active on the crime forum fl.l33t[.]su between 2016 and 2019. The user “Transfer” advertised and sold access to 911 from 2016 to 2018, amid many sales threads where they advertised expensive electronics and other consumer goods that were bought online with stolen credit cards.

In a 2017 discussion on fl.l33t[.]su, the user who picked the handle “527865713” could be seen answering private messages in response to help inquiries seeking someone at 911. That identity is tied to an individual who for years advertised the ability to receive and relay large wire transfers from China.

One ad from this user in 2016 offered a “China wire service” focusing on Western Union payments, where “all transfers are accepted in China.” The service charged 20 percent of all “scam wires,” unauthorized wire transfers resulting from bank account takeovers or scams like CEO impersonation schemes.

911 TODAY

In August 2021, 911’s biggest competitor — a 15-year-old proxy network built on malware-compromised PCs called VIP72 — abruptly closed up shop. Almost overnight, an overwhelming number of former VIP72 customers began shifting their proxy activities to 911.

That’s according to Riley Kilmer, co-founder of Spur.us — a security company that monitors anonymity services. Kilmer said 911 also gained an influx of new customers after the Jan. 2022 closure of LuxSocks, another malware-based proxy network.

“911’s user base skyrocketed after VIP72 and then LuxSocks went away,” Kilmer said. “And it’s not hard to see why. 911 and VIP72 are both Windows-based apps that operate in a similar way, where you buy private access to IPs.”

Kilmer said 911 is interesting because it appears to be based in China, while nearly all of the other major proxy networks are Russian-backed or Russian-based.

“They have two basic methods to get new IPs,” Kilmer said. “The free VPN apps, and the other is trojanized torrents. They’ll re-upload Photoshop and stuff like that so that it’s backdoored with the 911 proxy. They claim the proxy is bundled with legitimate software and that users all agree to their Terms of Service, meanwhile they can hide behind the claim that it was some affiliate who installed the software, not them.”

Kilmer said at last count, 911 had nearly 200,000 proxy nodes for sale, spanning more than 200 countries: The largest geographic concentration is the United States, where more than 42,000 proxies are currently for rent by the service.

PARTING THOUGHTS

Beware of “free” or super low-cost VPN services. Proper VPN services are not cheap to operate, so the revenue for the service has to come from somewhere. And there are countless “free” VPN services that are anything but, as we’ve seen with 911.

In general, 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. Many free VPN services will enlist users as VPN nodes for others to use, and some even offset costs by collecting and reselling data from their users.

All VPN providers claim to prioritize the privacy of their users, but many then go on to collect and store all manner of personal and financial data from those customers. Others are fairly opaque about their data collection and retention policies.

I’ve largely avoided wading into the fray about which VPN services are best, but there are so many shady and just plain bad ones out there that I’d be remiss if I didn’t mention one VPN provider whose business practices and transparency of operation consistently distinguish them from the rest. If maintaining your privacy and anonymity are primary concerns for you as a VPN user, check out Mullvad.net.

Let me make clear that KrebsOnSecurity does not have any financial or business ties to this company (for the avoidance of doubt, this post doesn’t even link to them). I mention it only because I’ve long been impressed with their candor and openness, and because Mullvad goes out of its way to discourage customers from sharing personal or financial data.

To that end, Mullvad will even accept mailed payments of cash to fund accounts, quite a rarity these days. More importantly, the service doesn’t ask users to share phone numbers, email addresses or any other personal information. Nor does it require customers to create passwords: Each subscription can be activated just by entering a Mullvad account number (woe to those who lose their account number).

I wish more companies would observe this remarkably economical security practice, which boils down to the mantra, “You don’t have to protect what you don’t collect.”

Update, July 24, 11:15 a.m. ET: 911’s homepage now includes a banner saying the service has halted new registrations and payments. “We are reviewing our network and adding a series of security measures to prevent misuse of our services,” the message reads. “Proxy balance top-up and new user registration are closed. We are reviewing every existing user, to ensure their usage is legit and [in] compliance with our Terms of Service.”

Update, July 30, 10:07 a.m. ET: 911 announced on July 28 that it is permanently closing down, following a series of data breaches this month that 911 says resulted in the deletion of customer data.