Entries Tagged "denial of service"

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DOS Attack Against Los Angeles Schools

Yesterday, the city of Los Angeles closed all of its schools—over 1,000 schools—because of a bomb threat. It was a hoax.

LA officials defended the move, with that city’s police chief dismissing the criticism as “irresponsible.”

“It is very easy in hindsight to criticize a decision based on results the decider could never have known,” Chief Charlie Beck said at a news conference.

I wrote about this back in 2007, where I called it CYA security: given the choice between overreacting to a threat and wasting everyone’s time, and underreacting and potentially losing your job, it’s easy to overreact.

What’s interesting is that New York received the same threat, and treated it as the hoax it was. Why the difference?

EDITED TO ADD (12/17): Best part of the story: the e-mailer’s address was madbomber@cock.li.

EDITED TO ADD (1/13): There have been copycats.

Posted on December 16, 2015 at 6:28 AMView Comments

History of Hacktivism

Nice article by Dorothy Denning.

Hacktivism emerged in the late 1980s at a time when hacking for fun and profit were becoming noticeable threats. Initially it took the form of computer viruses and worms that spread messages of protest. A good example of early hacktivism is “Worms Against Nuclear Killers (WANK),” a computer worm that anti-nuclear activists in Australia unleashed into the networks of the National Aeronautics and Space Administration and the US Department of Energy in 1989 to protest the launch of a shuttle which carried radioactive plutonium.

By the mid-1990s, denial of service (DoS) attacks had been added to the hacktivist’s toolbox, usually taking the form of message or traffic floods. In 1994, journalist Joshua Quittner lost access to his e-mail after thousands of messages slamming “capitalistic pig” corporations swamped his inbox, and a group called itself “The Zippies” flooded e-mail accounts in the United Kingdom with traffic to protest a bill that would have outlawed outdoor dance festivals. Then in 1995, an international group called Strano Network organized a one-hour “Net’strike” against French government websites to protest nuclear and social policies. At the designated time, participants visited the target websites and hit the “reload” button over and over in an attempt to tie up traffic to the sites.

Her conclusion comes as no surprise:

Hacktivism, including state-sponsored or conducted hacktivism, is likely to become an increasingly common method for voicing dissent and taking direct action against adversaries. It offers an easy and inexpensive means to make a statement and inflict harm without seriously risking prosecution under criminal law or a response under international law. Hacking gives non-state actors an attractive alternative to street protests and state actors an appealing substitute for armed attacks. It has become not only a popular means of activism, but also an instrument of national power that is challenging international relations and international law.

Posted on September 21, 2015 at 6:34 AMView Comments

China's "Great Cannon"

Interesting research: “An Analysis of China’s ‘Great Cannon.’

Abstract: On March 16th, 2015, the Chinese censorship apparatus employed a new tool, the “Great Cannon”, to engineer a denial-of-service attack on GreatFire.org, an organization dedicated to resisting China’s censorship. We present a technical analysis of the attack and what it reveals about the Great Cannon’s working, underscoring that in essence it constitutes a selective nation-state Man-in-the-Middle attack tool. Although sharing some code similarities and network locations with the Great Firewall, the Great Cannon is a distinct tool, designed to compromise foreign visitors to Chinese sites. We identify the Great Cannon’s operational behavior, localize it in the network topology, verify its distinctive side-channel, and attribute the system as likely operated by the Chinese government. We also discuss the substantial policy implications raised by its use, including the potential imposition on any user whose browser might visit (even inadvertently) a Chinese web site.

Posted on September 4, 2015 at 8:16 AMView Comments

China's Great Cannon

Citizen Lab has issued a report on China’s “Great Cannon” attack tool, used in the recent DDoS attack against GitHub.

We show that, while the attack infrastructure is co-located with the Great Firewall, the attack was carried out by a separate offensive system, with different capabilities and design, that we term the “Great Cannon.” The Great Cannon is not simply an extension of the Great Firewall, but a distinct attack tool that hijacks traffic to (or presumably from) individual IP addresses, and can arbitrarily replace unencrypted content as a man-in-the-middle.

The operational deployment of the Great Cannon represents a significant escalation in state-level information control: the normalization of widespread use of an attack tool to enforce censorship by weaponizing users. Specifically, the Cannon manipulates the traffic of “bystander” systems outside China, silently programming their browsers to create a massive DDoS attack. While employed for a highly visible attack in this case, the Great Cannon clearly has the capability for use in a manner similar to the NSA’s QUANTUM system, affording China the opportunity to deliver exploits targeting any foreign computer that communicates with any China-based website not fully utilizing HTTPS.

It’s kind of hard for the US to complain about this kind of thing, since we do it too.

More stories. Hacker News thread.

Posted on April 13, 2015 at 9:12 AMView Comments

Attributing the Sony Attack

No one has admitted taking down North Korea’s Internet. It could have been an act of retaliation by the US government, but it could just as well have been an ordinary DDoS attack. The follow-on attack against Sony PlayStation definitely seems to be the work of hackers unaffiliated with a government.

Not knowing who did what isn’t new. It’s called the “attribution problem,” and it plagues Internet security. But as governments increasingly get involved in cyberspace attacks, it has policy implications as well. Last year, I wrote:

Ordinarily, you could determine who the attacker was by the weaponry. When you saw a tank driving down your street, you knew the military was involved because only the military could afford tanks. Cyberspace is different. In cyberspace, technology is broadly spreading its capability, and everyone is using the same weaponry: hackers, criminals, politically motivated hacktivists, national spies, militaries, even the potential cyberterrorist. They are all exploiting the same vulnerabilities, using the same sort of hacking tools, engaging in the same attack tactics, and leaving the same traces behind. They all eavesdrop or steal data. They all engage in denial-of-service attacks. They all probe cyberdefences and do their best to cover their tracks.

Despite this, knowing the attacker is vitally important. As members of society, we have several different types of organizations that can defend us from an attack. We can call the police or the military. We can call on our national anti-terrorist agency and our corporate lawyers. Or we can defend ourselves with a variety of commercial products and services. Depending on the situation, all of these are reasonable choices.

The legal regime in which any defense operates depends on two things: who is attacking you and why. Unfortunately, when you are being attacked in cyberspace, the two things you often do not know are who is attacking you and why. It is not that everything can be defined as cyberwar; it is that we are increasingly seeing warlike tactics used in broader cyberconflicts. This makes defence and national cyberdefence policy difficult.

In 2007, the Israeli Air Force bombed and destroyed the al-Kibar nuclear facility in Syria. The Syrian government immediately knew who did it, because airplanes are hard to disguise. In 2010, the US and Israel jointly damaged Iran’s Natanz nuclear facility. But this time they used a cyberweapon, Stuxnet, and no one knew who did it until details were leaked years later. China routinely denies its cyberespionage activities. And a 2009 cyberattack against the United States and South Korea was blamed on North Korea even though it may have originated from either London or Miami.

When it’s possible to identify the origins of cyberattacks­—like forensic experts were able to do with many of the Chinese attacks against US networks­—it’s as a result of months of detailed analysis and investigation. That kind of time frame doesn’t help at the moment of attack, when you have to decide within milliseconds how your network is going to react and within days how your country is going to react. This, in part, explains the relative disarray within the Obama administration over what to do about North Korea. Officials in the US government and international institutions simply don’t have the legal or even the conceptual framework to deal with these types of scenarios.

The blurring of lines between individual actors and national governments has been happening more and more in cyberspace. What has been called the first cyberwar, Russia vs. Estonia in 2007, was partly the work of a 20-year-old ethnic Russian living in Tallinn, and partly the work of a pro-Kremlin youth group associated with the Russian government. Many of the Chinese hackers targeting Western networks seem to be unaffiliated with the Chinese government. And in 2011, the hacker group Anonymous threatened NATO.

It’s a strange future we live in when we can’t tell the difference between random hackers and major governments, or when those same random hackers can credibly threaten international military organizations.

This is why people around the world should care about the Sony hack. In this future, we’re going to see an even greater blurring of traditional lines between police, military, and private actions as technology broadly distributes attack capabilities across a variety of actors. This attribution difficulty is here to stay, at least for the foreseeable future.

If North Korea is responsible for the cyberattack, how is the situation different than a North Korean agent breaking into Sony’s office, photocopying a lot of papers, and making them available to the public? Is Chinese corporate espionage a problem for governments to solve, or should we let corporations defend themselves? Should the National Security Agency defend US corporate networks, or only US military networks? How much should we allow organizations like the NSA to insist that we trust them without proof when they claim to have classified evidence that they don’t want to disclose? How should we react to one government imposing sanctions on another based on this secret evidence? More importantly, when we don’t know who is launching an attack or why, who is in charge of the response and under what legal system should those in charge operate?

We need to figure all of this out. We need national guidelines to determine when the military should get involved and when it’s a police matter, as well as what sorts of proportional responses are available in each instance. We need international agreements defining what counts as cyberwar and what does not. And, most of all right now, we need to tone down all the cyberwar rhetoric. Breaking into the offices of a company and photocopying their paperwork is not an act of war, no matter who did it. Neither is doing the same thing over the Internet. Let’s save the big words for when it matters.

This essay previously appeared on TheAtlantic.com.

Jack Goldsmith responded to this essay.

Posted on January 7, 2015 at 11:16 AMView Comments

DDoSing a Cell Phone Network

Interesting research:

Abstract: The HLR/AuC is considered to be one of the most important network elements of a 3G network. It can serve up to five million subscribers and at least one transaction with HLR/AuC is required for every single phone call or data session. This paper presents experimental results and observations that can be exploited to perform a novel distributed denial of service attack in 3G networks that targets the availability of the HLR/AuC. More specifically, first we present an experiment in which we identified and proved some zero-day vulnerabilities of the 3G network that can be exploited by malicious actors to mount various attacks. For the purpose of our experiment, we have used off-the-shelf infrastructure and software, without any specialized modification. Based on the observations of the experiment, we reveal an Advanced Persistent Threat (APT) in 3G networks that aims to flood an HLR/AuC of a mobile operator. We also prove that the discovered APT can be performed in a trivial manner using commodity hardware and software, which is widely and affordably available.

The attack involves cloning SIM cards, then making multiple calls from different handsets in different locations with the same SIM card. This confuses the network into thinking that the same phone is in multiple places at once.

Note that this has not been tested in the field, but there seems no reason why it wouldn’t work.

There’s a lot of insecurity in the fact that cell phones and towers largely trust each other. The NSA and FBI use that fact for eavesdropping, and here it’s used for a denial-of-service attack.

Posted on February 26, 2014 at 6:55 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.