Posts Tagged: Arbor Networks


14
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.

prolexicattack

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 The problem isn’t with NTP itself, per se, but with certain outdated or hard-coded implementations of it that attackers can use to turn a relatively negligible attack into something much, much bigger.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 →


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.

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.

Continue reading →


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.

Continue reading →


14
Oct 10

Cyber Deterrence Group Urges Greater Disclosure, Transparency

A group tasked with devising strategies to deter cyber attacks is calling for mandatory public disclosure of fraud and hacking incidents by governments and organizations of all sizes, including banks.

The recommendations were a major thrust of a report issued earlier this month by the National Research Council, which was asked to examine the issue by the Office of the Director of National Intelligence. The 400-page document is actually well worth the time to read, or at least skim. The bulk of the paper addresses how solving the problems associated with cyber crime requires aligning incentives and liabilities so that those in the best position to fix the problems have an incentive to do so.

But to me, the most interesting and useful components of the report come at the end, where the group makes several broad policy recommendations, including:

  • Mitigating malware infections via ISPs by subsidized cleanup
  • Mandatory disclosure of fraud losses and security incidents
  • Mandatory disclosure of industrial control system incidents and intrusions
  • Aggregating reports of cyber espionage and reporting to the World Trade Organization

I don’t know how effective or realistic the last two recommendations would be, but as a reporter I’m naturally inclined toward disclosing data whenever possible. Loyal readers no doubt know where I stand on the first two points. I have long called for some kind of system in which ISPs are encouraged or given incentives to regularly scrub their networks for bot-infested customers and compromised Web sites.

And hardly a month goes by when I don’t hear from someone asking me where to find aggregated statistics on the costs of cybercrime and Internet banking fraud in the United States. The banks don’t have to publish reports of their losses, and although they are supposed to publish indicators of fraud (through suspicious activity reports) financial institutions seem to be spotty and begrudging about this level of reporting as well. Writing for SC Magazine earlier this summer, Charles Jeter of security software maker ESET penned a useful three part series on the lack of reporting by banks about the costs of online banking Trojans.

The free report is available at this link.

Speaking of global trends in cybercrime, Microsoft published its biannual Security Intelligence Report covering cybercrime activity it has observed in the first half of 2010. Anyone looking for granular data on which threats are most prevalent (at least from Microsoft’s perspective in scrubbing millions of PCs) should have a look at this informative report. Unsurprisingly, the United States (or more accurately — US-based ISPs) continues to lead the world in botnet infections.

While we’re on the subject of data breach and attack disclosure, now seems like a perfect time to mention that Arbor Networks is seeking additional perspective for its annual Worldwide Infrastructure Security Threat Report. Arbor is looking for a few clueful network administrators to anonymously share experiences and perspectives about operational risks and challenges involved in building, operating and defending large networks. If this describes you, check out their survey.