Posts Tagged: Hackforums

Oct 16

Source Code for IoT Botnet ‘Mirai’ Released

The source code that powers the “Internet of Things” (IoT) botnet responsible for launching the historically large distributed denial-of-service (DDoS) attack against KrebsOnSecurity last month has been publicly released, virtually guaranteeing that the Internet will soon be flooded with attacks from many new botnets powered by insecure routers, IP cameras, digital video recorders and other easily hackable devices.

The leak of the source code was announced Friday on the English-language hacking community Hackforums. The malware, dubbed “Mirai,” spreads to vulnerable devices by continuously scanning the Internet for IoT systems protected by factory default or hard-coded usernames and passwords.

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

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

Vulnerable devices are then seeded with malicious software that turns them into “bots,” forcing them to report to a central control server that can be used as a staging ground for launching powerful DDoS attacks designed to knock Web sites offline.

The Hackforums user who released the code, using the nickname “Anna-senpai,” told forum members the source code was being released in response to increased scrutiny from the security industry.

“When I first go in DDoS industry, I wasn’t planning on staying in it long,” Anna-senpai wrote. “I made my money, there’s lots of eyes looking at IOT now, so it’s time to GTFO [link added]. So today, I have an amazing release for you. With Mirai, I usually pull max 380k bots from telnet alone. However, after the Kreb [sic] DDoS, ISPs been slowly shutting down and cleaning up their act. Today, max pull is about 300k bots, and dropping.”

Sources tell KrebsOnSecurity that Mirai is one of at least two malware families that are currently being used to quickly assemble very large IoT-based DDoS armies. The other dominant strain of IoT malware, dubbed “Bashlight,” functions similarly to Mirai in that it also infects systems via default usernames and passwords on IoT devices.

According to research from security firm Level3 Communications, the Bashlight botnet currently is responsible for enslaving nearly a million IoT devices and is in direct competition with botnets based on Mirai.

“Both [are] going after the same IoT device exposure and, in a lot of cases, the same devices,” said Dale Drew, Level3’s chief security officer.
Continue reading →

Sep 16

Israeli Online Attack Service ‘vDOS’ Earned $600,000 in Two Years

vDOS  a “booter” service that has earned in excess of $600,000 over the past two years helping customers coordinate more than 150,000 so-called distributed denial-of-service (DDoS) attacks designed to knock Web sites offline — has been massively hacked, spilling secrets about tens of thousands of paying customers and their targets.

The vDOS database, obtained by at the end of July 2016, points to two young men in Israel as the principal owners and masterminds of the attack service, with support services coming from several young hackers in the United States.

The vDos home page.

The vDos home page.

To say that vDOS has been responsible for a majority of the DDoS attacks clogging up the Internet over the past few years would be an understatement. The various subscription packages to the service are sold based in part on how many seconds the denial-of-service attack will last. And in just four months between April and July 2016, vDOS was responsible for launching more than 277 million seconds of attack time, or approximately 8.81 years worth of attack traffic.

Let the enormity of that number sink in for a moment: That’s nearly nine of what I call “DDoS years” crammed into just four months. That kind of time compression is possible because vDOS handles hundreds — if not thousands — of concurrent attacks on any given day.

Although I can’t prove it yet, it seems likely that vDOS is responsible for several decades worth of DDoS years. That’s because the data leaked in the hack of vDOS suggest that the proprietors erased all digital records of attacks that customers launched between Sept. 2012 (when the service first came online) and the end of March 2016.


The hack of vDOS came about after a source was investigating a vulnerability he discovered on a similar attack-for-hire service called PoodleStresser. The vulnerability allowed my source to download the configuration data for PoodleStresser’s attack servers, which pointed back to api.vdos-s[dot]com. PoodleStresser, as well as a large number of other booter services, appears to rely exclusively on firepower generated by vDOS.

From there, the source was able to exploit a more serious security hole in vDOS that allowed him to dump all of the service’s databases and configuration files, and to discover the true Internet address of four rented servers in Bulgaria (at that are apparently being used to launch the attacks sold by vDOS. The DDoS-for-hire service is hidden behind DDoS protection firm Cloudflare, but its actual Internet address is

vDOS had a reputation on cybercrime forums for prompt and helpful customer service, and the leaked vDOS databases offer a fascinating glimpse into the logistical challenges associated with running a criminal attack service online that supports tens of thousands of paying customers — a significant portion of whom are all trying to use the service simultaneously.

Multiple vDOS tech support tickets were filed by customers who complained that they were unable to order attacks on Web sites in Israel. Responses from the tech support staff show that the proprietors of vDOS are indeed living in Israel and in fact set the service up so that it was unable to attack any Web sites in that country — presumably so as to not attract unwanted attention to their service from Israeli authorities. Here are a few of those responses:

(‘4130′,’Hello `d0rk`,\r\nAll Israeli IP ranges have been blacklisted due to security reasons.\r\n\r\nBest regards,\r\nP1st.’,’03-01-2015 08:39),

(‘15462′,’Hello `g4ng`,\r\nMh, neither. I\’m actually from Israel, and decided to blacklist all of them. It\’s my home country, and don\’t want something to happen to them :)\r\n\r\nBest regards,\r\nDrop.’,’11-03-2015 15:35),

(‘15462′,’Hello `roibm123`,\r\nBecause I have an Israeli IP that is dynamic.. can\’t risk getting hit/updating the blacklist 24/7.\r\n\r\nBest regards,\r\nLandon.’,’06-04-2015 23:04),

(‘4202′,’Hello `zavi156`,\r\nThose IPs are in israel, and we have all of Israel on our blacklist. Sorry for any inconvinience.\r\n\r\nBest regards,\r\nJeremy.’,’20-05-2015 10:14),

(‘4202′,’Hello `zavi156`,\r\nBecause the owner is in Israel, and he doesn\’t want his entire region being hit offline.\r\n\r\nBest regards,\r\nJeremy.’,’20-05-2015 11:12),

(‘9057′,’There is a option to buy with Paypal? I will pay more than $2.5 worth.\r\nThis is not the first time I am buying booter from you.\r\nIf no, Could you please ask AplleJack? I know him from Israel.\r\nThanks.’,’21-05-2015 12:51),

(‘4120′,’Hello `takedown`,\r\nEvery single IP that\’s hosted in israel is blacklisted for safety reason. \r\n\r\nBest regards,\r\nAppleJ4ck.’,’02-09-2015 08:57),


As we can see from the above responses from vDOS’s tech support, the owners and operators of vDOS are young Israeli hackers who go by the names P1st a.k.a. P1st0, and AppleJ4ck. The two men market their service mainly on the site hackforums[dot]net, selling monthly subscriptions using multiple pricing tiers ranging from $20 to $200 per month. AppleJ4ck hides behind the same nickname on Hackforums, while P1st goes by the alias “M30w” on the forum.

Some of P1st/M30W's posts on Hackforums regarding his service vDOS.

Some of P1st/M30W’s posts on Hackforums regarding his service vDOS.

vDOS appears to be the longest-running booter service advertised on Hackforums, and it is by far and away the most profitable such business. Records leaked from vDOS indicate that since July 2014, tens of thousands of paying customers spent a total of more than $618,000 at the service using Bitcoin and PayPal.

Incredibly, for brief periods the site even accepted credit cards in exchange for online attacks, although it’s unclear how much the site might have made in credit card payments because the information is not in the leaked databases.

The Web server hosting vDOS also houses several other sites, including huri[dot]biz, ustress[dot]io, and vstress[dot]net. Virtually all of the administrators at vDOS have an email account that ends in v-email[dot]org, a domain that also is registered to an Itay Huri with a phone number that traces back to Israel.

The proprietors of vDOS set their service up so that anytime a customer asked for technical assistance the site would blast a text message to six different mobile numbers tied to administrators of the service, using an SMS service called Two of those mobile numbers go to phones in Israel. One of them is the same number listed for Itay Huri in the Web site registration records for v-email[dot]org; the other belongs to an Israeli citizen named Yarden Bidani. Neither individual responded to requests for comment.

The leaked database and files indicate that vDOS uses Mailgun for email management, and the secret keys needed to manage that Mailgun service were among the files stolen by my source. The data shows that vDOS support emails go to itay@huri[dot]biz, and


The $618,000 in earnings documented in the vDOS leaked logs is almost certainly a conservative income figure. That’s because the vDOS service actually dates back to Sept 2012, yet the payment records are not available for purchases prior to 2014. As a result, it’s likely that this service has made its proprietors more than $1 million.

vDOS does not currently accept PayPal payments. But for several years until recently it did, and records show the proprietors of the attack service worked assiduously to launder payments for the service through a round-robin chain of PayPal accounts.

They did this because at the time PayPal was working with a team of academic researchers to identify, seize and shutter PayPal accounts that were found to be accepting funds on behalf of booter services like vDOS. Anyone interested in reading more on their success in making life harder for these booter service owners should check out my August 2015 story, Stress-Testing the Booter Services, Financially.

People running dodgy online services that violate PayPal’s terms of service generally turn to several methods to mask the true location of their PayPal Instant Payment Notification systems. Here is an interesting analysis of how popular booter services are doing so using shell corporations, link shortening services and other tricks.

Turns out, AppleJ4ck and p1st routinely recruited other forum members on Hackforums to help them launder significant sums of PayPal payments for vDOS each week.

“The paypals that the money are sent from are not verified,” AppleJ4ck says in one recruitment thread. “Most of the payments will be 200$-300$ each and I’ll do around 2-3 payments per day.”

vDos co-owner AppleJ4ck recruiting Hackforums members to help launder PayPal payments for his booter service.

vDos co-owner AppleJ4ck recruiting Hackforums members to help launder PayPal payments for his booter service.

It is apparent from the leaked vDOS logs that in July 2016 the service’s owners implemented an additional security measure for Bitcoin payments, which they accept through Coinbase. The data shows that they now use an intermediary server ( to handle Coinbase traffic. When a Bitcoin payment is received, Coinbase notifies this intermediary server, not the actual vDOS servers in Bulgaria.

A server situated in the middle and hosted at a U.S.-based address from Digital Ocean then updates the database in Bulgaria, perhaps because the vDOS proprietors believed payments from the USA would attract less interest from Coinbase than huge sums traversing through Bulgaria each day. Continue reading →

Nov 15

TalkTalk, Script Kids & The Quest for ‘OG’

So you’ve got two-step authentication set up to harden the security of your email account (you do, right?). But when was the last time you took a good look at the security of your inbox’s recovery email address? That may well be the weakest link in your email security chain, as evidenced by the following tale of a IT professional who saw two of his linked email accounts recently hijacked in a bid to steal his Twitter identity.

Screen Shot 2015-10-24 at 10.08.01 AMEarlier this week, I heard from Chris Blake, a longtime KrebsOnSecurity reader from the United Kingdom. Blake reached out because I’d recently written about a character of interest in the breach at British phone and broadband provider TalkTalk: an individual using the Twitter handle “@Fearful“.

Blake proceeded to explain how that same Fearful account had belonged to him for some time until May 2015, when an elaborate social engineering attack on his Internet service provider (ISP) allowed the current occupant of the account to swipe it out from under him.

On May 11, Blake received a text message on his mobile stating that his Microsoft Outlook account password had been changed. A minute later, he got another text from Microsoft saying his two-factor authentication (texted login codes to his phone) had been removed. After that, he could no longer log in to his Outlook account because someone had changed his password and removed his recovery email address (changing it to a free and disposable account).

Minutes after that, someone tweeted out the message from his account: “This twitter account is officially operated by Elliott G.” The tweet prior to that one mentions Blake by name and is a response to an inquiry to the Microsoft Store before the account was taken. The alias on Blake’s @Fearful account was changed to “Glubz”.

Blake said it took some time to figure out how the miscreant had hijacked his Twitter and Outlook accounts. Turns out, the recovery email address that he’d supplied for his Outlook account was to an email address at his local ISP, and the attacker executed the first step in the hijack by tricking a customer service employee at the ISP into redirecting his messages.

The attacker, apparently another person with a British accent, called Blake’s ISP pretending to be Blake and said he was locked out of his inbox. Could the ISP please change the domain name system (DNS) settings on his domain and associated mail account?

According to Blake, an investigation into the incident at the ISP shows that the customer service rep asked the caller to verify any other email addresses associated with Blake’s ISP account, and after some waiting the support employee actually read off a few of them. Seconds later, the attacker sent an email to the support person that spoofed one of those email addresses. After that, Blake’s ISP complied with the request, changing the DNS settings on his account to settings that the caller supplied for an account at


With all of the access to other accounts that one’s inbox affords, the attacker in this case could have done some serious damage and cost Blake a lot of money. So why was he only interested in Blake’s Twitter account?

Short usernames are something of a prestige or status symbol for many youngsters, and some are willing to pay surprising amounts of money for them. Known as “OG” (short for “original” and also “original gangster”) in certain circles online, these can be usernames for virtually any service, from email accounts at Webmail providers to social media services like Instagram, Snapchat, Twitter and Youtube. People who traffic in OG accounts prize them because they can make the account holder appear to have been a savvy, early adopter of the service before it became popular and before all of the short usernames were taken.

“I didn’t realize this was even a thing until all this happened,” Blake said of the demand for OG accounts. “It wasn’t until the day after my email accounts were hacked that I realized it was really my Twitter account he was after.”

As it happens, the guy who is currently squatting on Blake’s @Fearful Twitter account — a young wanna-be hacker who uses the nickname “Glubz” — is very publicly in the business of selling hijacked OG accounts. In the screen shot below, we can see Glubz on the script kiddie-friendly online community Hackforums promoting his “OG Store,” in which he sells “Snapchats,” Email accounts and “Youtubes” for $10-$40 apiece, payable via Bitcoin or PayPal. The bottom of the message includes a link to Glubz’s personal site — elliottg[dot]net (also hosted at Continue reading →

Aug 15

Stress-Testing the Booter Services, Financially

The past few years have witnessed a rapid proliferation of cheap, Web-based services that troublemakers can hire to knock virtually any person or site offline for hours on end. Such services succeed partly because they’ve enabled users to pay for attacks with PayPal. But a collaborative effort by PayPal and security researchers has made it far more difficult for these services to transact with their would-be customers.



By offering a low-cost, shared distributed denial-of-service (DDoS) attack infrastructure, these so-called “booter” and “stresser” services have attracted thousands of malicious customers and are responsible for hundreds of thousands of attacks per year. Indeed, KrebsOnSecurity has repeatedly been targeted in fairly high-volume attacks from booter services — most notably a service run by the Lizard Squad band of miscreants who took responsibility for sidelining the Microsoft xBox and Sony Playstation on Christmas Day 2014.

For more than two months in the summer 2014, researchers with George Mason University, UC Berkeley’s International Computer Science Institute, and the University of Maryland began following the money, posing as buyers of nearly two dozen booter services in a bid to discover the PayPal accounts that booter services were using to accept payments. In response to their investigations, PayPal began seizing booter service PayPal accounts and balances, effectively launching their own preemptive denial-of-service attacks against the payment infrastructure for these services.

PayPal will initially limit reported merchant accounts that are found to violate its terms of service (turns out, accepting payments for abusive services is a no-no). Once an account is limited, the merchant cannot withdraw or spend any of the funds in their account. This results in the loss of funds in these accounts at the time of freezing, and potentially additional losses due to opportunity costs the proprietors incur while establishing a new account. In addition, PayPal performed their own investigation to identify additional booter domains and limited accounts linked to these domains as well.

The efforts of the research team apparently brought some big-time disruption for nearly two-dozen of the top booter services. The researchers said that within a day or two following their interventions, they saw the percentage of active booters quickly dropping from 70 to 80 percent to around 50 percent, and continuing to decrease to a low of around 10 percent that were still active.


While some of the booter services went out of business shortly thereafter, more than a half-dozen shifted to accepting payments via Bitcoin (although the researchers found that this dramatically cut down on the services’ overall number of active customers). Once the target intervention began, they found the average lifespan of an account dropped to around 3.5 days, with many booters’ PayPal accounts only averaging around two days before they were no longer used again.

The researchers also corroborated the outages by monitoring hacker forums where the services were marketed, chronicling complaints from angry customers and booter service operators who were inconvenienced by the disruption (see screen shot galley below).

A booter service proprietor advertising his wares on the forum Hackforums complains about Paypal repeatedly limiting his account.

A booter service proprietor advertising his wares on the forum Hackforums complains about Paypal repeatedly limiting his account.

Another booter seller on Hackforums whinges about PayPal limiting the account he uses to accept attack payments from customers.

Another booter seller on Hackforums whinges about PayPal limiting the account he uses to accept attack payments from customers.

"It's a shame PayPal had to shut us down several times causing us to take money out of our own pocket to purchase servers, hosting and more," says this now-defunct booter service to its former customers.

“It’s a shame PayPal had to shut us down several times causing us to take money out of our own pocket to purchase servers, hosting and more,” says this now-defunct booter service to its former customers.

Deadlyboot went dead after the PayPal interventions. So sad.

Deadlyboot went dead after the PayPal interventions. So sad.

Daily attacks from Infected Stresser dropped off precipitously following the researchers' work.

Daily attacks from Infected Stresser dropped off precipitously following the researchers’ work.

As I’ve noted in past stories on booter service proprietors I’ve tracked down here in the United States, many of these service owners and operators are kids operating within easy reach of U.S. law enforcement. Based on the aggregated geo-location information provided by PayPal, the researchers found that over 44% of the customer and merchant PayPal accounts associated with booters are potentially owned by someone in the United States. Continue reading →

May 15

PayIvy Sells Your Online Accounts Via PayPal

Normally, if one wishes to buy stolen account credentials for paid online services like Netflix, Hulu, XBox Live or Spotify, the buyer needs to visit a cybercrime forum or drop into a dark Web marketplace that only accepts Bitcoin as payment. Increasingly, however, these accounts are showing up for sale at Payivy[dot]com, an open Web marketplace that happily accepts PayPal in exchange for a variety of stolen accounts.

A PayIvy seller advertising Netflix accounts for a dollar apiece.

A PayIvy seller advertising Netflix accounts for a dollar apiece. Unlike most sites selling hacked accounts, this one takes PayPal.

Marketed and sold by a Hackforums user named “Sh1eld” as a supposed method of selling ebooks and collecting payments for affiliate marketers, PayIvy has instead become a major conduit for hawking stolen accounts and credentials for a range of top Web services.

There is no central index of items for sale via PayIvy per se, but this catalog of cached sales threads offers a fairly representative glimpse: License keys for Adobe and Microsoft software products, user account credentials in bulk for services like Hulu, Netflix, Spotify, DirecTV and HBO Go, as well as a raft of gaming accounts at Origin, Steam, PlayStation and XBox Live. Other indexes at and PayIvy’s page at Reddit reveal similar results.

It’s not clear how or why PayPal isn’t shutting down most of these merchants, but some of the sellers clearly are testing things to see how far they can push it: In just five minutes of searching online, I found several PayIvy sellers who were accepting PayPal payments via PayIvy for…wait for it…hijacked PayPal accounts! The fact that PayIvy takes PayPal as payment means that buyers can purchase hacked accounts with [stolen] credit cards — or, worse yet, stolen PayPal accounts.

Jack Christin, Jr., associate general counsel at PayPal, said while the site itself is not in violation of its Acceptable Use Policies (AUP), there have been cases where PayPal has identified accounts selling goods that violate its policy and in those cases, the company has exited those merchants from its system.  Continue reading →

Dec 14

Who’s in the Lizard Squad?

The core members of a group calling itself “Lizard Squad” — which took responsibility for attacking Sony’s Playstation and Microsoft‘s Xbox networks and knocking them offline for Christmas Day — want very much to be recognized for their actions. So, here’s a closer look at two young men who appear to be anxious to let the world know they are closely connected to the attacks.

Kim Dotcom offers Lizard Squad members vouchers to stop the attack.

Kim Dotcom offers Lizard Squad members vouchers to stop the attack.

The LizardSquad reportedly only called off their attacks after MegaUpload founder Kim Dotcom offered the group some 3,000 vouchers for his content hosting service. The vouchers sell for $99 apiece, meaning that Dotcom effectively offered the group the equivalent of $300,000 to stop their seige.

On Dec. 26, BBC Radio aired an interview with two young men who claimed to have been involved in the attacks. The two were referred to in the interview only as “Member 1” and “Member 2,” but both have each given on-camera interviews previously (more on that in a bit).

The BBC’s Stephen Nolan asks Member 2, “It was nothing really to do with exposing a company for the greater good? You took the money and you ran, didn’t you, like a petty criminal?”

M2: “Well, we didn’t really expect money from it in the first place. If we really cared about money we could have used the twitter accounts that we generated over 50,000 followers within 24-48 hours we could have used that for monetization, you know? We could have easily sent out a couple of linked….profiles or whatever where each click could gain us three to six cents.”

Vinnie Omari, speaking to Sky News on Dec. 27.

Vinnie Omari, speaking to Sky News on Dec. 27.

Nolan: “So why did you take the vouchers, then?

M2: “It was just an offer. It’s hard to say. It was just a one-time thing. It’s $300,000 worth of vouchers.”

Nolan: “Dirty, grubby, greed?”

M2: “Well, that’s what happens, I’m afraid. That’s what it is like in the security business.”

Member2, the guy that does most of the talking in the BBC interview, appears to be a 22-year-old from the United Kingdom named Vinnie Omari. Sky News ran an on-camera interview with Omari on Dec. 27, quoting him as a “computer security analyst” as he talks about the attacks by LizardSquad and their supposed feud with a rival hacker gang.

The same voice can be heard on this video from Vinnie’s Youtube channel, in which he enthuses about hackforums[dot]net, a forum that is overrun with teenage wannabe hackers who spend most of their time trying to impress, attack or steal from one another.

In a thread on Hackforums that Omari began on Dec. 26 using the Hackforums username “Vinnie” Omari says he’s been given vouchers from Kim Dotcom’s Mega, and wonders if the Hackforums rules allow him to sell the vouchers on the forum.

Hackforums user "Vinnie" asks about selling MegaUpload vouchers.

Hackforums user “Vinnie” asks about selling MegaUpload vouchers.


Continue reading →

Jul 14

Even Script Kids Have a Right to Be Forgotten

Indexeus, a new search engine that indexes user account information acquired from more than 100 recent data breaches, has caught many in the hacker underground off-guard. That’s because the breached databases crawled by this search engine are mostly sites frequented by young ne’er-do-wells who are just getting their feet wet in the cybercrime business.



Indexeus boasts that it has a searchable database of “over 200 million entries available to our customers.” The site allows anyone to query millions of records from some of the larger data breaches of late — including the recent break-ins at Adobe and Yahoo! — listing things like email addresses, usernames, passwords, Internet address, physical addresses, birthdays and other information that may be associated with those accounts.

Who are Indexeus’s target customers? Denizens of hackforums[dot]net, a huge forum that is overrun by novice teenage hackers (a.k.a “script kiddies”) from around the world who are selling and buying a broad variety of services designed to help attack, track or otherwise harass people online.

Few services are as full of irony and schadenfreude as Indexeus. You see, the majority of the 100+ databases crawled by this search engine are either from hacker forums that have been hacked, or from sites dedicated to offering so-called “booter” services — powerful servers that can be rented to launch denial-of-service attacks aimed at knocking Web sites and Web users offline.

The brains behind Indexeus — a gaggle of young men in their mid- to late teens or early 20s — envisioned the service as a way to frighten fellow hackers into paying to have their information removed or “blacklisted” from the search engine. Those who pay “donations” of approximately $1 per record (paid in Bitcoin) can not only get their records expunged, but that price also buys insurance against having their information indexed by the search engine in the event it shows up in future database leaks. Continue reading →

Feb 14

The New Normal: 200-400 Gbps DDoS Attacks

Over the past four years, KrebsOnSecurity has been targeted by countless denial-of-service attacks intended to knock it offline. Earlier this week, KrebsOnSecurity was hit by easily the most massive and intense such attack yet — a nearly 200 Gbps assault leveraging a simple attack method that industry experts say is becoming alarmingly common.


At issue is a seemingly harmless feature built into many Internet servers known as the Network Time Protocol (NTP), which is used to sync the date and time between machines on a network. The problem isn’t with NTP itself, per se, but with certain outdated or hard-coded implementations of it that attackers can use to turn a relatively negligible attack into something much, much bigger. Symantec‘s writeup on this threat from December 2013 explains the problem succinctly:

Similar to DNS amplification attacks, the attacker sends a small forged packet that requests a large amount of data be sent to the target IP Address. In this case, the attackers are taking advantage of the monlist command.  Monlist is a remote command in older version of NTP that sends the requester a list of the last 600 hosts who have connected to that server.  For attackers the monlist query is a great reconnaissance tool.  For a localized NTP server it can help to build a network profile.  However, as a DDoS tool, it is even better because a small query can redirect megabytes worth of traffic.

Matthew Prince, the CEO of Cloudflare — a company that helps Web sites stay online in the face of huge DDoS attacks — blogged Thursday about a nearly 400 Gbps attack that recently hit one of the company’s customers and leveraged NTP amplification. Prince said that while Cloudflare “generally [was] able to mitigate the attack, it was large enough that it caused network congestion in parts of Europe.”

“Monday’s DDoS proved these attacks aren’t just theoretical. To generate approximately 400Gbps of traffic, the attacker used 4,529 NTP servers running on 1,298 different networks,” Prince wrote. “On average, each of these servers sent 87Mbps of traffic to the intended victim on CloudFlare’s network. Remarkably, it is possible that the attacker used only a single server running on a network that allowed source IP address spoofing to initiate the requests. An attacker with a 1 Gbps connection can theoretically generate more than 200Gbps of DDoS traffic.” Continue reading →