Posts Tagged: DDoS


20
May 13

Conversations with a Bulletproof Hoster

Criminal commerce on the Internet would mostly grind to a halt were it not for the protection offered by so-called “bulletproof hosting” providers – the online equivalent of offshore havens where shady dealings go ignored. Last month I had an opportunity to interview a provider of bulletproof services for one of the Web’s most notorious cybercrime forums, and who appears to have been at least partly responsible for launching what’s been called the largest cyber attack the Internet has ever seen.

Off-Sho.re's intro to Darkode

Off-Sho.re’s intro post to Darkode

Earlier this year, the closely-guarded English-language crime forum darkode.com was compromised and came under a series of heavy distributed denial-of-service (DDoS) attacks aimed at keeping it offline. Around that same time, darkode.com welcomed a new member — a bulletproof hosting broker aptly named “Off-sho.re” — who promised to defend the site from future DDoS attacks.

Off-sho.re also said he could offer more robust and crime-friendly hosting services than darkode’s previous provider — Santrex, literally an offshore hosting facility located in the Seychelles, a 115-island country that spans an archipelago in the Indian Ocean. Off-sho.re’s timing was perfect: Darkode desperately needed both, and Off-sho.re seemed to know his stuff, so he was admitted to the forum and given stewardship of the site’s defense and hosting.

Off-sho.re recruits Stophaus members on darkode.

Off-sho.re recruits Stophaus members on darkode.

STOPHAUS V. SPAMHAUS

Of course, to successfully defend a network against DDoS attacks one must know a great deal about how to launch such assaults. Indeed, Off-sho.re was an integral member of Stophaus, an upstart group of bulletproof hosters that banded together in March to launch a massive Internet attack against anti-spam group Spamhaus.org.

Hundreds of ISPs route or deny traffic based in part on Spamhaus’s blacklists of known, cybercrime-friendly ISPs, and Stophaus formed in response to Spamhaus’s listing of bulletproof hosting provider in particular: A network known alternatively as CB3ROB, a.k.a. “Cyberbunker” because it operated from a heavily fortified NATO bunker in The Netherlands.

Off-sho.re is moderator of the Stophaus forum, and not long after joining darkode.com, he was recruiting fellow darkode members for the Stophaus cause. Stophaus’s records show that another core member was “0ptik,” a competing bulletproof hosting provider. Spamhaus had listed dozens of Optik’s domains, as well as virtually all of the IP address ranges Off-sho.re had rented at abuse-friendly Romanian hosting provider Voxility. It was payback time.

In late March, Spamhaus became the target of what experts called one of the largest computer attacks on the Internet. The method of attack — a DNS amplification attack — was similar to that first seen used in attacks more than a decade ago that targeted the heart of the Internet’s routing system, except that it was by most accounts much larger.

Off-sho.re calls Spamhaus assault "our prank."

Off-sho.re calls Spamhaus assault “our prank.”

“DNS amplification attacks can bring up to 140 Gbps to a single resource from a single controller,” Off-sho.re wrote in a darkode.com posting less than 24 hours after the attack on Spamhaus began. “The beauty of it [is] that the ‘bots’ are just open DNS resolvers in the world.” Linking to a writeup from Cloudflare.com about the attack, Off-sho.re stated that “Some BP hosters were lately united, check out our latest prank.”

Last month, authorities in Spain arrested Sven Kamphuis, a 35-year-old Dutch man, thought to be responsible for coordinating the unprecedented attack on Spamhaus. According to Spamhaus, Kamphuis made claims about being his own independent country in the Republic of Cyberbunker. But according to Off-Sho.re, Kamphuis was just the public face of the movement. “Sven didn’t attack anyone,” Off-Sho.re wrote in an online chat with KrebsOnSecurity.

If Kamphuis was just a mouthpiece, who was responsible for the attack? What is interesting about the Stophaus movement is that Off-sho.re very well may have prompted Spamhaus to finally place CB3ROB/Cyberbunker at the top of its World’s Worst Spam-Support ISPs list, a move that helped to precipitate this conflict.

According to Spamhaus, while Cyberbunker and Spamhaus certainly have a bit of a history together, Cyberbunker wasn’t really a focus of Spamhaus’s blocking efforts until the fall of 2012. That’s when Spamhaus began noticing a large number of malware and botnet control servers being stood up inside of Cyberbunker’s Internet address ranges.

“We didn’t really notice these guys at CB3ROB much until last fall, when they started hosting botnet controllers, malware droppers and a lot of pharma spam stuff,” said a Spamhaus member who would only give his name as “Barry.” “Before that, it was mainly routing for some Chinese guys – Vincent Chan – fake Chinese products.”

Off-sho.re sells BP hosting out of Cyberbunker

Off-sho.re selling BP hosting out of Cyberbunker

Oddly enough, this coincides with Off-sho.re’s entrance on the bulletproof hosting scene (at least as advertised on crime forums). In his introduction post to Darkode, Off-sho.re  referenced his bulletproof hosting sales threads at two Russian-language forums — expoit.in and damagelab.org. In these threads, which began in Sept. 2012, Off-sho.re advertised the ability to host ZeuS and SpyEye botnet command and control networks for between $99 and $199 per month, and bulletproof domain registration from $30 per month. More importantly, Off-sho.re proudly announced that he was offering a premiere BP hosting service for $400 a month that was housed in an old NATO bunker in Holland and that used IP addresses assigned to CB3ROB (see screenshot to left).

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19
Feb 13

DDoS Attack on Bank Hid $900,000 Cyberheist

A Christmas Eve cyberattack against the Web site of a regional California financial institution helped to distract bank officials from an online account takeover against one of its clients, netting thieves more than $900,000.

Ascent1At approximately midday on December 24, 2012, organized cyber crooks began moving money out of corporate accounts belonging to Ascent Builders, a construction firm based in Sacramento, Calif. In short order, the company’s financial institution – San Francisco-based Bank of the West — came under a large distributed denial of service (DDoS) attack, a digital assault which disables a targeted site using a flood of junk traffic from compromised PCs.

KrebsOnSecurity contacted Ascent Builders on the morning of Dec. 26 to inform them of the theft, after interviewing one of the money mules used in the scam. Money mules are individuals who are willingly or unwittingly recruited to help the fraudsters launder stolen money and transfer the funds abroad. The mule in this case had been hired through a work-at-home job offer after posting her resume to a job search site, and said she suspected that she’d been conned into helping fraudsters.

Ascent was unaware of the robbery at the time, but its bank would soon verify that a series of unauthorized transactions had been initiated on the 24th and then again on the 26th. The money mule I spoke with was just one of 62 such individuals in the United States recruited to haul the loot stolen from Ascent. Most of the mules in this case were sent transfers of between $4,000 and $9,000, but several of them had bank accounts tied to businesses, to which the crooks wired huge transfers from Ascent’s account; five of the fraudulent transfers were for amounts ranging from $80,000 to $100,000.

Mark Shope, president of Ascent Builders, said that when the company’s controller originally went online on the morning of Dec. 24 to check the firm’s accounts, her browser wouldn’t let her access the bank’s page. She didn’t know it at the time, but her computer was being remotely controlled by the attackers’ malware, which blocked her from visiting the bank’s site.

“It said the bank was offline for 24 hours, and we couldn’t get in to the site,” Shope said. “We called the bank and they said everything was fine.”

But soon enough, everything would not be fine from Bank of the West’s end. Not long after putting through a batch of fraudulent automated clearing house (ACH) and wire transfers from Ascent’s accounts, the fraudsters initiated a DDoS attack against the bank’s Web site, effectively knocking it offline. It’s not clear what tactics or botnets may have been used in the DDoS attack, but the cyberheist+DDoS approach matches the profile of cybercrime gangs using the Gameover Trojan – a ZeuS Trojan variant that has been tied to numerous DDoS attacks initiated to distract attention from high-dollar cyberheists.

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8
Aug 12

Triple DDoS vs. KrebsOnSecurity

“When nobody hates you, nobody knows you’re alive.” – Diplomacy, by Chris Smither

During the last week of July, a series of steadily escalating cyber attacks directed at my Web site and hosting provider prevented many readers from being able to reach the site or read the content via RSS. Sorry about that. What follows is a post-mortem on those digital sieges, which featured a mix of new and old-but-effective attack methods.

Junk traffic sent by a DNS amplification attack.

I still don’t know who was attacking my site or why. It’s not as if the perpetrator(s) sent a love letter along with the traffic flood. There was one indication that a story I published just hours before the attacks began — about a service for mass-registering domain names used for malware, spam and other dodgy business — may have struck a nerve: In one of the attacks, all of the assailing systems were instructed to load that particular story many times per second.

Oddly enough, the activity began just one day after I’d signed up with Prolexic. The Hollywood, Fla. based company helps businesses fend off distributed denial of service (DDoS) attacks, assaults in which miscreants knock targeted sites offline by flooding them with garbage traffic. Prolexic was among several anti-DDoS companies that offered to help earlier this year, when KrebsOnSecurity.com came under a separate spate of debilitating attacks.

The first DDoS campaigns consisted of several hundred systems repeatedly requesting image-heavy pages on my site. Prolexic’s analysts say the traffic signatures of these attacks matched that of a family of kits sold in the underground that allow anyone to quickly create their own botnet specifically for launching DDoS attacks. Both are believed to have been created by the same individual(s) behind the Dirt Jumper DDoS toolkit. The traffic signatures from the attack strongly suggest the involvement of two Dirt Jumper progeny: Di-BoTNet and Pandora.

Image courtesy Prolexic

Pandora is the latest in the Dirt Jumper family, and features four different attack methods. According to Prolexic, the one used against KrebsOnSecurity.com was Attack Type 4, a.k.a “Max Flood”; this method carries a fairly unique signature of issuing POST requests against a server that are over a million bytes in length.

Pandora’s creators boast that it only takes 10 PCs infected with the DDoS bot to bring down small sites, and about 30 bots to put down a mid-sized site that lacks protection against DDoS attacks. They claim 1,000 Pandora bots are enough to bring Russian search engine giant yandex.ru to a crawl, but that strikes me as a bit of salesmanship and exaggeration. Prolexic said more than 1,500 Pandora-infected bots were used in the assault on my site.

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19
Jul 12

Top Spam Botnet, “Grum,” Unplugged

Nearly four years after it burst onto the malware scene, the notorious Grum spam botnet has been disconnected from the Internet. Grum has consistently been among the top three biggest spewers of junk email, a crime machine capable of blasting 18 billion messages per day and responsible for sending about one-third of all spam.

Source: Symantec Message Labs

The takedown, while long overdue, is another welcome example of what the security industry can accomplish cooperatively and without the aid of law enforcement officials. Early press coverage of this event erroneously attributed part of the takedown to Dutch authorities, but police in the Netherlands said they were not involved in this industry-led effort.

The Grum ambush began in earnest several weeks ago at the beginning of July, following an analysis published by security firm FireEye, a Milpitas, Calif. based company that has played a big role in previous botnet takedowns, including Mega-D/Ozdok, Rustock, Srizbi.

Atif Mushtaq, senior staff scientist at FireEye, said the company had some initial success in notifying ISPs that were hosting control networks for Grum: The Dutch ISP Ecatel responded favorably, yanking the plug on two control servers. But Mushtaq said the ISPs where Grum hosted its other control servers — networks in Russia and Panama — proved harder to convince.

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18
Jul 12

Cyberheist Smokescreen: Email, Phone, SMS Floods

It was early October 2011, and I was on the treadmill checking email from my phone when I noticed several hundred new messages had arrived since I last looked at my Gmail inbox just 20 minutes earlier. I didn’t know it at the time, but my account was being used to beta test a private service now offered openly in the criminal underground that can be hired to create highly disruptive floods of junk email, text messages and phone calls.

Many businesses request some kind of confirmation from their bank whenever high-dollar transfers are initiated. These confirmations may be sent via text message or email, or the business may ask their bank to call them to verify requested transfers. The attack that hit my inbox was part of an offering that crooks can hire to flood each medium of communication, thereby preventing a targeted business from ever receiving or finding alerts from their bank.

Shortly after the email barrage began, I fired off a note to Google‘s public relations folks, asking for advice and assistance. Thankfully, my phone line was not a subject of the attack, and I was able to communicate what I was seeing to Google’s team. They worked to fight the attack for the better part of that day, during which time my inbox received tens of thousands of emails, burying hundreds of legitimate emails in page after page of junk messages (in the screen shot above, the note to Google spokesman Jay Nancarrow is at the top of the junk message pile).

What was most surprising about these messages was that many of them contained fairly spammy subject lines that should have been easily caught by Google’s junk mail filters. Each junk message contained nothing but pages full of garbled letters and numbers; the text of each missive resembled an encrypted message.

Google’s engineers managed to block a majority of the junk messages after about six hours, but the company declined to talk about what caused the attack to succeed. It took many more hours to sift through the junk messages to fish out the ones I wanted.

“This isn’t about a hole in Gmail or an exploit — it’s more a matter of spam dynamics and what may be able to get through more easily under certain circumstances,” Nancarrow said. “As a result, we can’t provide specifics that could aid spammers in trying new campaigns.”

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29
May 12

White House Aims to Stoke Botnet Fight

The Obama administration will hold a public meeting at the White House on Wednesday to discuss industry and government efforts to combat botnet activity. Among those is a pilot program to share information about botnet victims between banks and Internet service providers, according to sources familiar with the event.

The gathering will draw officials from The White House, US Department of Commerce and Department of Homeland Security, as well as private-sector executives from an entity formed in February called the Industry Botnet Group. The IBG counts among its members trade associations, companies and privacy organizations that are working to create a voluntary model that ISPs can use to notify customers with infected computers.

Although a number of ISPs already notify customers of bot infections, there is no uniform method for reporting these events. Attendees at Wednesday’s meeting are expected to announce — among other things — an information sharing pilot between ISPs and financial institutions that are part of the Financial Services Information Sharing and Analysis Center, an industry consortium dedicated to disseminating data on cyber threats facing banks.

The pilot to be announced this week will draw on a nascent extension of IODEF, an Internet standard developed by the Anti-Phishing Working Group to share data about phishing attacks in a common format that can be processed automatically and across multiple languages. Continue reading →


30
Nov 11

DDoS Attacks Spell ‘Gameover’ for Banks, Victims in Cyber Heists

The FBI is warning that computer crooks have begun launching debilitating cyber attacks against banks and their customers as part of a smoke screen to prevent victims from noticing simultaneous high-dollar cyber heists.

The bureau says the attacks coincide with corporate account takeovers perpetrated by thieves who are using a modified version of the ZeuS Trojan called “Gameover.” The rash of thefts come after a series of heavy spam campaigns aimed at deploying the malware, which arrives disguised as an email from the National Automated Clearing House Association (NACHA), a not-for-profit group that develops operating rules for organizations that handle electronic payments. The ZeuS variant steals passwords and gives attackers direct access to the victim’s PC and network.

In several recent attacks, as soon as thieves wired money out of a victim organization’s account, the victim’s public-facing Internet address was targeted by a network attack, leaving employees at the organization unable to browse the Web.

A few of the attacks have included an odd twist that appears to indicate the perpetrators are using money mules in the United States for at least a portion of the heists. According to an FBI advisory, some of the unauthorized wire transfers from victim organizations have been transmitted directly to high-end jewelry stores, “wherein the money mule comes to the actual store to pick up his $100K in jewels (or whatever dollar amount was wired).”

The advisory continues:

“Investigation has shown the perpetrators contact the high-end jeweler requesting to purchase precious stones and high-end watches. The perpetrators advise they will wire the money to the jeweler’s account and someone will come to pick up the merchandise. The next day, a money mule arrives at the store, the jeweler confirms the money has been transferred or is listed as ‘pending’ and releases the merchandise to the mule. Later on, the transaction is reversed or cancelled (if the financial institution caught the fraud in time) and the jeweler is out whatever jewels the money mule was able to obtain.”

The attackers also have sought to take out the Web sites of victim banks. Jose Nazario, manager of security research at Arbor Networks, a company that specializes in helping organizations weather large cyber attacks, said that although many of the bank sites hit belong to small to mid-sized financial institutions, the thieves also have taken out some of the larger banks in the course of recent e-heists.

“It’s a disturbing trend,” Nazario said.

Nazario said the handful of attacks he’s aware of in the past two weeks have involved distributed denial-of-service (DDoS) assaults launched with the help of “Dirt Jumper” or “Russkill” botnets. Dirt Jumper is a commercial crimeware kit that is sold for a few hundred bucks on the hacker underground, and is made to be surreptitiously installed on hacked PCs. The code makes it easy for the botnet owner to use those infected systems to overwhelm targeted sites with junk traffic (KrebsOnSecurity.com was the victim of a Dirt Jumper botnet attack earlier this month).

Security experts aren’t certain about the strategy behind the DDoS attacks, which are noisy and noticeable to both victims and their banks. One theory is that the perpetrators are hoping the outages will distract the banks and victims.

“The belief is the DDoS is used to deflect attention from the wire transfers as well to make them unable to reverse the transactions (if found),” the FBI said.

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1
Aug 11

Digital Hit Men for Hire

Cyber attacks designed to knock Web sites off line happen every day, yet shopping for a virtual hit man to launch one of these assaults has traditionally been a dicey affair. That’s starting to change: Hackers are openly competing to offer services that can take out a rival online business or to settle a score.

An ad for a DDoS attack service.

There are dozens of underground forums where members advertise their ability to execute debilitating “distributed denial-of-service” or DDoS attacks for a price. DDoS attack services tend to charge the same prices, and the average rate for taking a Web site offline is surprisingly affordable: about $5 to $10 per hour; $40 to $50 per day; $350-$400 a week; and upwards of $1,200 per month.

Of course, it pays to read the fine print before you enter into any contract. Most DDoS services charge varying rates depending on the complexity of the target’s infrastructure, and how much lead time the attack service is given to size up the mark. Still, buying in bulk always helps: One service advertised on several fraud forums offered discounts for regular and wholesale customers.

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23
Jun 11

Financial Mogul Linked to DDoS Attacks

Pavel Vrublevsky, the embattled co-founder of ChronoPay — Russia’s largest online payments processor — has reportedly fled the country after the arrest of a suspect who confessed that he was hired by Vrublevsky to launch a debilitating cyber attack against a top ChronoPay competitor.

KrebsOnSecurity has featured many stories on Vrublevsky’s role as co-founder of the infamous rogue online pharmacy Rx-Promotion, and on his efforts to situate ChronoPay as a major processor for purveyors of “scareware,” software that uses misleading computer virus infection alerts to frighten users into paying for worthless security software.  But these activities have largely gone overlooked by Russian law enforcement officials, possibly because the consequences have not impacted Russian citizens.

In the summer of 2010, rumors began flying in the Russian blogosphere that Vrublevsky had hired a hacker to launch a distributed denial of service (DDoS) attack against Assist, the company that was processing payments for Aeroflot, Russia’s largest airline. Aeroflot had opened its contract for processing payments to competitive bidding, and ChronoPay was competing against Assist and several other processors. The attack on Assist occurred just weeks before Aeroflot was to decide which company would win the contract; it so greatly affected Assist’s operations that the company was unable to process payments for extended periods of time. Citing the downtime in processing as a factor in its decision, Aeroflot ultimately awarded the contract to neither ChronoPay nor Assist, but instead to Alfa-Bank, the largest private bank in Russia.

According to documents leaked to several Russian security blogs, investigators with the Russian Federal Security Service (FSB) this month arrested a St. Petersburg man named Igor Artimovich in connection with the attacks. The documents indicate that Artimovich — known in hacker circles by the handle “Engel” — confessed to having used his botnet to attack Assist after receiving instructions and payment from Vrublevsky. The same blogs say Vrublevsky has fled the country. Sources close to the investigation say he is currently in the Maldives. Vrublevsky did not respond to multiple requests for comment.

"Topol Mailer" botnet interface allegedly used by Artimovich.

The allegations against Artimovich and Vrublevsky were supported by evidence collected by Russian computer forensics firm Group-IB, which said it assisted the FSB with the investigation. Group-IB presented detailed information on the malware and control servers used to control more than 10,000 infected PCs, and shared with investigators screen shots of the botnet control panel (pictured at left) allegedly used to coordinate the DDoS attack against Assist. Group-IB said Artimovich’s botnet also was used to attack several rogue pharmacy programs that were competing with Rx-Promotion, including Glavmed and Spamit (these attacks also were observed by security firm SecureWorks in February).

This DDoS saga is the latest chapter in a fascinating drama playing out between the two largest rogue Internet pharmacies: Vrublevsky’s Rx-Promotion and Glavmed (a.k.a. “Spamit”), a huge pharma affiliate program run by Igor Gusev, the man who co-founded ChronoPay with Vrublevsky in 2003. Continue reading →