Posts Tagged: Jesse Wu


18
Jan 17

Who is Anna-Senpai, the Mirai Worm Author?

On September 22, 2016, this site was forced offline for nearly four days after it was hit with “Mirai,” a malware strain that enslaves poorly secured Internet of Things (IoT) devices like wireless routers and security cameras into a botnet for use in large cyberattacks. Roughly a week after that assault, the individual(s) who launched that attack — using the name “Anna-Senpai” — released the source code for Mirai, spawning dozens of copycat attack armies online.

After months of digging, KrebsOnSecurity is now confident to have uncovered Anna-Senpai’s real-life identity, and the identity of at least one co-conspirator who helped to write and modify the malware.

The Hackforums post that includes links to the Mirai source code.

Mirai co-author Anna-Senpai leaked the source code for Mirai on Sept. 30, 2016.

Before we go further, a few disclosures are probably in order. First, this is easily the longest story I’ve ever written on this blog. It’s lengthy because I wanted to walk readers through my process of discovery, which has taken months to unravel. The details help in understanding the financial motivations behind Mirai and the botnet wars that preceded it. Also, I realize there are a great many names to keep track of as you read this post, so I’ve included a glossary.

The story you’re reading now is the result of hundreds of hours of research.  At times, I was desperately seeking the missing link between seemingly unrelated people and events; sometimes I was inundated with huge amounts of information — much of it intentionally false or misleading — and left to search for kernels of truth hidden among the dross.  If you’ve ever wondered why it seems that so few Internet criminals are brought to justice, I can tell you that the sheer amount of persistence and investigative resources required to piece together who’s done what to whom (and why) in the online era is tremendous.

As noted in previous KrebsOnSecurity articles, botnets like Mirai are used to knock individuals, businesses, governmental agencies, and non-profits offline on a daily basis. These so-called “distributed denial-of-service (DDoS) attacks are digital sieges in which an attacker causes thousands of hacked systems to hit a target with so much junk traffic that it falls over and remains unreachable by legitimate visitors. While DDoS attacks typically target a single Web site or Internet host, they often result in widespread collateral Internet disruption.

A great deal of DDoS activity on the Internet originates from so-called ‘booter/stresser’ services, which are essentially DDoS-for-hire services which allow even unsophisticated users to launch high-impact attacks.  And as we will see, the incessant competition for profits in the blatantly illegal DDoS-for-hire industry can lead those involved down some very strange paths, indeed.

THE FIRST CLUES

The first clues to Anna-Senpai’s identity didn’t become clear until I understood that Mirai was just the latest incarnation of an IoT botnet family that has been in development and relatively broad use for nearly three years.

Earlier this summer, my site was hit with several huge attacks from a collection of hacked IoT systems compromised by a family of botnet code that served as a precursor to Mirai. The malware went by several names, including “Bashlite,” “Gafgyt,” “Qbot,” “Remaiten,” and “Torlus.”

All of these related IoT botnet varieties infect new systems in a fashion similar to other well-known Internet worms — propagating from one infected host to another. And like those earlier Internet worms, sometimes the Internet scanning these systems perform to identify other candidates for inclusion into the botnet is so aggressive that it constitutes an unintended DDoS on the very home routers, Web cameras and DVRs that the bot code is trying to subvert and recruit into the botnet. This kind of self-defeating behavior will be familiar to those who recall the original Morris Worm, NIMDA, CODE RED, Welchia, Blaster and SQL Slammer disruptions of yesteryear.

Infected IoT devices constantly scan the Web for other IoT things to compromise, wriggling into devices that are protected by little more than insecure factory-default settings and passwords. The infected devices are then forced to participate in DDoS attacks (ironically, many of the devices most commonly infected by Mirai and similar IoT worms are security cameras).

Mirai’s ancestors had so many names because each name corresponded to a variant that included new improvements over time. In 2014, a group of Internet hooligans operating under the banner “lelddos” very publicly used the code to launch large, sustained attacks that knocked many Web sites offline.

The most frequent target of the lelddos gang were Web servers used to host Minecraft, a wildly popular computer game sold by Microsoft that can be played from any device and on any Internet connection.

The object of Minecraft is to run around and build stuff, block by large pixelated block. That may sound simplistic and boring, but an impressive number of people positively adore this game – particularly pre-teen males. Microsoft has sold more than a 100 million copies of Minecraft, and at any given time there are over a million people playing it online. Players can build their own worlds, or visit a myriad other blocky realms by logging on to their favorite Minecraft server to play with friends.

Image: Minecraft.net

Image: Minecraft.net

A large, successful Minecraft server with more than a thousand players logging on each day can easily earn the server’s owners upwards of $50,000 per month, mainly from players renting space on the server to build their Minecraft worlds, and purchasing in-game items and special abilities.

Perhaps unsurprisingly, the top-earning Minecraft servers eventually attracted the attention of ne’er-do-wells and extortionists like the lelddos gang. Lelddos would launch a huge DDoS attack against a Minecraft server, knowing that the targeted Minecraft server owner was likely losing thousands of dollars for each day his gaming channel remained offline.

Adding urgency to the ordeal, many of the targeted server’s loyal customers would soon find other Minecraft servers to patronize if they could not get their Minecraft fix at the usual online spot.

Robert Coelho is vice president of ProxyPipe, Inc., a San Francisco company that specializes in protecting Minecraft servers from attacks.

“The Minecraft industry is so competitive,” Coelho said. “If you’re a player, and your favorite Minecraft server gets knocked offline, you can switch to another server. But for the server operators, it’s all about maximizing the number of players and running a large, powerful server. The more players you can hold on the server, the more money you make. But if you go down, you start to lose Minecraft players very fast — maybe for good.”

In June 2014, ProxyPipe was hit with a 300 gigabit per second DDoS attack launched by lelddos, which had a penchant for publicly taunting its victims on Twitter just as it began launching DDoS assaults at the taunted.

The hacker group "lelddos" tweeted at its victims before launching huge DDoS attacks against them.

The hacker group “lelddos” tweeted at its victims before launching huge DDoS attacks against them.

At the time, ProxyPipe was buying DDoS protection from Reston, Va. -based security giant Verisign. In a quarterly report published in 2014, Verisign called the attack the largest it had ever seen, although it didn’t name ProxyPipe in the report – referring to it only as a customer in the media and entertainment business.

Verisign said the 2014 attack was launched by a botnet of more than 100,000 servers running on SuperMicro IPMI boards. Days before the huge attack on ProxyPipe, a security researcher published information about a vulnerability in the SuperMicro devices that could allow them to be remotely hacked and commandeered for these sorts of attacks.

THE CENTRALITY OF PROTRAF

Coelho recalled that in mid-2015 his company’s Minecraft customers began coming under attack from a botnet made up of IoT devices infected with Qbot. He said the attacks were directly preceded by a threat made by a then-17-year-old Christopher “CJ” Sculti, Jr., the owner and sole employee of a competing DDoS protection company called Datawagon.

Datawagon also courted Minecraft servers as customers, and its servers were hosted on Internet space claimed by yet another Minecraft-focused DDoS protection provider — ProTraf Solutions.

CJ Sculti, Jr.

Christopher “CJ” Sculti, Jr.

According to Coelho, ProTraf was trying to woo many of his biggest Minecraft server customers away from ProxyPipe. Coelho said in mid-2015, Sculti reached out to him on Skype and said he was getting ready to disable Coelho’s Skype account. At the time, an exploit for a software weakness in Skype was being traded online, and this exploit could be used to remotely and instantaneously disable any Skype account.

Sure enough, Coelho recalled, his Skype account and two others used by co-workers were shut off just minutes after that threat, effectively severing a main artery of support for ProxyPipe’s customers – many of whom were accustomed to communicating with ProxyPipe via Skype.

“CJ messaged me about five minutes before the DDoS started, saying he was going to disable my skype,” Coelho said. “The scary thing about when this happens is you don’t know if your Skype account has been hacked and under control of someone else or if it just got disabled.”

Once ProxyPipe’s Skype accounts were disabled, the company’s servers were hit with a massive, constantly changing DDoS attack that disrupted ProxyPipe’s service to its Minecraft server customers. Coelho said within a few days of the attack, many of ProxyPipe’s most lucrative Minecraft servers had moved over to servers protected by ProTraf Solutions.

“In 2015, the ProTraf guys hit us offline tons, so a lot of our customers moved over to them,” Coelho said. “We told our customers that we knew [ProTraf] were the ones doing it, but some of the customers didn’t care and moved over to ProTraf anyway because they were losing money from being down.”

I found Coelho’s story fascinating because it eerily echoed the events leading up to my Sept. 2016 record 620 Gbps attack. I, too, was contacted via Skype by Sculti — on two occasions. The first was on July 7, 2015, when Sculti reached out apropos of nothing to brag about scanning the Internet for IoT devices running default usernames and passwords, saying he had uploaded some kind of program to more than a quarter-million systems that his scans found.

Here’s a snippet of that conversation:

July 7, 2015:

21:37 CJ: http://krebsonsecurity.com/2015/06/crooks-use-hacked-routers-to-aid-cyberheists/
21:37 CJ: vulnerable routers are a HUGE issue
21:37 CJ: a few months ago
21:37 CJ: I scanned the internet with a few sets of defualt logins
21:37 CJ: for telnet
21:37 CJ: and I was able to upload and execute a binary
21:38 CJ: on 250k devices
21:38 CJ: most of which were routers
21:38 Brian Krebs: o_0

The second time I heard from Sculti on Skype was Sept. 20, 2016 — the day of my 620 Gbps attack. Sculti was angry over a story I’d just published that mentioned his name, and he began rather saltily maligning the reputation of a source and friend who had helped me with that story.

Indignant on behalf of my source and annoyed at Sculti’s rant, I simply blocked his Skype account from communicating with mine and went on with my day. Just minutes after that conversation, however, my Skype account was flooded with thousands of contact requests from compromised or junk Skype accounts, making it virtually impossible to use the software for making phone calls or instant messaging.

Six hours after that Sept. 20 conversation with Sculti, the huge 620 Gbps DDoS attack commenced on this site. Continue reading →


19
Oct 16

Spreading the DDoS Disease and Selling the Cure

Earlier this month a hacker released the source code for Mirai, a malware strain that was used to launch a historically large 620 Gbps denial-of-service attack against this site in September. That attack came in apparent retribution for a story here which directly preceded the arrest of two Israeli men for allegedly running an online attack for hire service called vDOS. Turns out, the site where the Mirai source code was leaked had some very interesting things in common with the place vDOS called home.

The domain name where the Mirai source code was originally placed for download — santasbigcandycane[dot]cx — is registered at the same domain name registrar that was used to register the now-defunct DDoS-for-hire service vdos-s[dot]com.

Normally, this would not be remarkable, since most domain registrars have thousands or millions of domains in their stable. But in this case it is interesting mainly because the registrar used by both domains — a company called namecentral.comhas apparently been used to register just 38 domains since its inception by its current owner in 2012, according to a historic WHOIS records gathered by domaintools.com (for the full list see this PDF).

What’s more, a cursory look at the other domains registered via namecentral.com since then reveals a number of other DDoS-for-hire services, also known as “booter” or “stresser” services.

It’s extremely odd that someone would take on the considerable cost and trouble of creating a domain name registrar just to register a few dozen domains. It costs $3,500 to apply to the Internet Corporation for Assigned Names and Numbers (ICANN) for a new registrar authority. The annual fee for being an ICANN-approved registrar is $4,000, and then there’s a $800 quarterly fee for smaller registrars. In short, domain name registrars generally need to register many thousands of new domains each year just to turn a profit.

Many of the remaining three dozen or so domains registered via Namecentral over the past few years are tied to vDOS. Before vDOS was taken offline it was massively hacked, and a copy of the user and attack database was shared with KrebsOnSecurity. From those records it was easy to tell which third-party booter services were using vDOS’s application programming interface (API), a software function that allowed them to essentially resell access to vDOS with their own white-labeled stresser.

And a number of those vDOS resellers were registered through Namecentral, including 83144692[dot].com — a DDoS-for-hire service marketed at Chinese customers. Another Namecentral domain — vstress.net — also was a vDOS reseller.

Other DDoS-for-hire domains registered through Namecentral include xboot[dot]net, xr8edstresser[dot]com, snowstresser[dot]com, ezstress[dot]com, exilestress[dot]com, diamondstresser[dot]net, dd0s[dot]pw, rebelsecurity[dot]net, and beststressers[dot]com.

WHO RUNS NAMECENTRAL?

Namecentral’s current owner is a 19-year-old California man by the name of Jesse Wu. Responding to questions emailed from KrebsOnSecurity, Wu said Namecentral’s policy on abuse was inspired by Cloudflare, the DDoS protection company that guards Namecentral and most of the above-mentioned DDoS-for-hire sites from attacks of the very kind they sell.

“I’m not sure (since registrations are automated) but I’m going to guess that the reason you’re interested in us is because some stories you’ve written in the past had domains registered on our service or otherwise used one of our services,” Wu wrote.

“We have a policy inspired by Cloudflare’s similar policy that we ourselves will remain content-neutral and in the support of an open Internet, we will almost never remove a registration or stop providing services, and furthermore we’ll take any effort to ensure that registrations cannot be influenced by anyone besides the actual registrant making a change themselves – even if such website makes us uncomfortable,” Wu said. “However, as a US based company, we are held to US laws, and so if we receive a valid court issued order to stop providing services to a client, or to turn over/disable a domain, we would happily comply with such order.”

Wu’s message continued:

“As of this email, we have never received such an order, we have never been contacted by any law enforcement agency, and we have never even received a legitimate, credible abuse report. We realize this policy might make us popular with ‘dangerous’ websites but even then, if we denied them services, simply not providing them services would not make such website stop existing, they would just have to find some other service provider/registrar or change domains more often. Our services themselves cannot be used for anything harmful – a domain is just a string of letters, and the rest of our services involve website/ddos protection/ecommerce security services designed to protect websites.”

Taking a page from Cloudflare, indeed. I’ve long taken Cloudflare to task for granting DDoS protection for countless DDoS-for-hire services, to no avail. I’ve maintained that Cloudflare has a blatant conflict of interest here, and that the DDoS-for-hire industry would quickly blast itself into oblivion because the proprietors of these attack services like nothing more than to turn their attack cannons on each other. Cloudflare has steadfastly maintained that picking and choosing who gets to use their network is a slippery slope that it will not venture toward.

Although Mr. Wu says he had nothing to do with the domains registered through Namecentral, public records filed elsewhere raise serious unanswered questions about that claim.

In my Sept. 8 story, Israeli Online Attack Service Earned $600,000 in Two Years, I explained that the hacked vDOS database indicated the service was run by two 18-year-old Israeli men. At some point, vDOS decided to protect all customer logins to the service with an extended validation (EV) SSL certificate. And for that, it needed to show it was tied to an actual corporate entity.

My investigation into those responsible for supporting vDOS began after I took a closer look at the SSL certificate that vDOS-S[dot]com used to encrypt customer logins. On May 12, 2015, Digicert.com issued an EV SSL certificate for vDOS, according to this record.

As we can see, whoever registered that EV cert did so using the business name VS NETWORK SERVICES LTD, and giving an address in the United Kingdom of 217 Blossomfield Rd., Solihull, West Midlands.

Who owns VS NETWORK SERVICES LTD? According this record from Companies House UK — an official ledger of corporations located in the United Kingdom — the director of the company was listed as one Thomas McGonagall. 

Records from Companies House UK on the firm responsible for registering vDOS's SSL certificate.

Records from Companies House UK on the firm responsible for registering vDOS’s SSL certificate.

This individual gave the same West Midlands address, stating that he was appointed to VS Network Services on May 12, 2015, and that his birthday was in May 1988. A search in Companies House for Thomas McGonagall shows that a person by that same name and address also was listed that very same day as a director for a company called REBELSECURITY LTD.

If we go back even further into the corporate history of this mysterious Mr. McGonagall we find that he was appointed director of NAMECENTRAL LTD on August 18, 2014. Mr. McGonagall’s birthday is listed as December 1995 in this record, and his address is given as 29 Wigorn Road, 29 Wigorn Road, Smethwick, West Midlands, United Kingdom, B67 5HL. Also on that same day, he was appointed to run EZSTRESS LTD, a company at the same Smethwick, West Midlands address.

Strangely enough, those company names correspond to other domains registered through Namecentral around the same time the companies were created, including rebelsecurity[dot]net, ezstress[dot]net.

Asked to explain the odd apparent corporate connections between Namecentral, vDOS, EZStress and Rebelsecurity, Wu chalked that up to an imposter or potential phishing attack.

“I’m not sure who that is, and we are not affiliated with Namecentral Ltd.,” he wrote. “I looked it up though and it seems like it is either closed or has never been active. From what you described it could be possible someone set up shell companies to try and get/resell EV certs (and someone’s failed attempt to set up a phishing site for us – thanks for the heads up).”

Interestingly, among the three dozen or so domains registered through Namecentral.com is “certificateavenue.com,” a site that until recently included nearly identical content as Namecentral’s home page and appears to be aimed at selling EV certs. Certificateavenue.com was responding as of early-October, but it is no longer online.

I also asked Wu why he chose to become a domain registrar when it appeared he had very few domains to justify the substantial annual costs of maintaining a registrar business. Continue reading →