DDoS Defense Archive

Network-based attacks are rising in popularity, a new report says, claiming that botnets, DNS as DDoS are key attack vectors.

CenturyLink’s new whitepaper argues that organisations struggle to identify, block and mitigate threats on time, and even though visibility and monitoring is important – acting is paramount.

Necurs, Emotet and TheMoon are considered the biggest, and most dangerous botnets. Their strength lies in the fact that they’re easy to use, can be accessed remotely and anonymously.

Domain Name Server (DNS) is often overlooked as a potential attack vector, CenturyLink claims, adding that DNS tunnelling, as an attack type, is on the rise. When it comes to DDoS attacks, the company has spotted an increase in burst attacks which less up to a minute.

“As companies focus on digital innovation, they are entering a world of unprecedented threat and risk,” said Mike Benjamin, head of CenturyLink’s threat research and operations division, Black Lotus Labs.

“Threats continue to evolve, as do bad actors. Well-financed nation-states and focused criminal groups have replaced the lone-wolf troublemaker and less sophisticated attackers motivated by chatroom fame. Thankfully, through our actionable insights, we can defend our network and those of our customers against these evolving threats.”

Companies in the United States, China, India, Russia and Vietnam were most frequently under attack in the first half of the year.

Source: https://www.itproportal.com/news/risk-of-network-based-attacks-continues-to-grow/

IoT networks can both amplify and be the targets of distributed denial of service (DDoS) or botnet attacks. Architect resilient solutions to properly secure your devices.

Cybercriminals have many different ways of exploiting network vulnerabilities and weak spots in our cyber defenses. Considering that the number of devices we use on a daily basis is growing, more avenues of exploitation will be open to cybercriminals — unless we close those pathways.

Distributed Denial of Service, or “DDoS,” attacks on IoT networks via botnets have been especially alarming and difficult to counter. Let’s have a closer look at DDoS attacks, botnets and ways of protecting against them.

The Anatomy of a DDoS Attack

A simple principle governs a “denial-of-service” attack: attackers attempt to deny service to legitimate users. Some typical examples might include attackers overwhelming a server or cluster with requests, disrupting everyone’s access to the site or focusing the attack on a particular target who will be denied access.

With DDoS, the attacker usually has one of three goals:

  1. To cause destruction or destructive change to network components
  2. To destroy configuration information
  3. To consume non-renewable or limited resources

DDoS attacks can be performed on their own or as part of a more massive attack on an organization. It usually targets bandwidth or processing resources like memory and CPU cycles. However, the type of DDoS attacks where we often see IoT devices used is a botnet attack.

What Makes a Botnet Attack So Destructive?

A botnet is a group of connected computers that work together on performing repetitive tasks, and it doesn’t necessarily have a malicious purpose. Unfortunately, it’s possible for an attacker to take control of a botnet by infecting a vulnerable device with malware. Then they can use the network as a group of devices to perform DDoS attacks that can be much more dangerous, depending on the number of mechanisms involved. What’s more, since IoT devices often interact in the physical world in ways that other IT devices don’t, it’s difficult to monitor and safeguard them.

If we strive to protect IoT devices the same way we protect our conventional IT devices, there will invariably be faults in the system that cybercriminals might exploit. To eliminate vulnerabilities, we must think of IoT protection in its own terms and take into account the various types of IoT use when we do.

Defending Against an IoT Botnet Attack

Even though the threat of botnets can’t wholly be eradicated, there are still ways to limit the impact and the scope of these attacks by taking preventative actions. One of them is placing IoT devices on a segmented network protected from external traffic. It’s also crucial to start monitoring the systems and invest in developing intrusion detection processes which would go a long way in warning a user that the system is being compromised.

How can each layer of your IoT solution stack be architected not to trust any other part naively? Think about that as you design your solution. Find ways to make your network more resilient. Model botnet attacks and test disaster scenario responses.

In addition to network segmentation and testing, we also shouldn’t forget fundamental security measures, such as timely firmware and software patching and the ability to control who can access a particular device, which every IoT solution should take care of.

The Search for a One-Size-Fits-All Security Solution

IoT is a developing technology that we must make as secure as possible, tempering its frenetic evolution with necessary security protocols and standards. Considering how quickly it’s being woven into our everyday lives, businesses and homes, IoT developers, manufacturers, distributors and consumers must work together to eliminate common IoT vulnerabilities and ensure that each device is as secure as it can be from emerging threats.

Source: https://www.iotforall.com/iot-botnets-ddos-attack-architecture/

Attacks leveraging compromised IoT devices are growing in size, scale and frequency, report security experts at F-Secure and Trend Micro, with Mirai-related botnets a major source of trouble.

Almost three years after the Mirai internet of things (IoT) botnet was deployed in a distributed denial of service (DDoS) attack against domain name system (DNS) provider Dyn, driving multiple websites offline, its descendants dominate the IoT threat landscape, according to multiple cyber security experts.

Mirai’s source code was released on an underground forum at the start of October 2016, prompting immediate fears of huge and sustained DDoS events, and according to F-Secure, it is now the most common type of malware seen by its honeypots – decoy servers set up to lure attackers and gather their information.

“Three years after Mirai first appeared, and two years after WannaCry, it shows that we still haven’t solved the problems leveraged in those outbreaks,” said F-Secure principal researcher Jarno Niemela, who has just released a report exploring the overall threat landscape in the first six months of 2019.

“The insecurity of the IoT, for one, is only getting more profound, with more and more devices cropping up all the time and then being co-opted into botnets,” said Niemela.

Meanwhile, writing on the supplier’s Simply Security blog, Trend Micro’s threat communications lead, Jon Clay, said monetisation of IoT threats was mainly through botnets, adding that there was “a lot of chatter within multiple undergrounds” to raise awareness of this particular attack surface.

“For consumers and organisations, be aware that devices you own are a likely target for attacks, and most likely today to be added into an existing botnet,” he said. “Mirai is the dominant IoT threat today and is likely to continue as malicious actors create variants of this malware.”

According to a newly released Trend Micro report, the impact of Mirai on the hacking community has been “profound”, virtually eliminating any incentive for malware writers to develop new IoT botnet code.

“Mirai has become the only code a would-be IoT attacker needs, which, in turn, stifled the creativity, so to speak, of cyber criminals in developing original malware,” wrote the report’s authors. “Most ‘new’ IoT botnets today are mere modifications of the Mirai code base.

“Mirai has limited the demand – and therefore the criminal market – for the same kinds of products. Few criminals are willing to pay for something they can already get for free. Therefore, non-Mirai botnets for sale are uncommon. However, this situation may change if a criminal offers an IoT botnet that has a monetisation plan built in. We have not seen this yet, but it’s not an entirely unlikely scenario.”

F-Secure said its honeypot network recorded 12 times more attack events during the first six months of this year than in the first half of 2018, with the increase driven by traffic targeting the IoT Telnet (760 million attack events) and UPnP(611 million) protocols, with most coming from devices infected with Mirai.

Meanwhile, the SMB protocol, which is more commonly used by the Eternal exploit family – first used during the 2017 WannaCry outbreak – to spread ransomware and trojans, was behind 556 million events.

According to F-Secure, a recent development has been new variants of Mirai that are engineered to infect enterprise IoT devices, such as digital signage screens or wireless presentation systems. This is a source of concern because it allows attackers access to higher-bandwidth internet connections, which means the scale of any resulting DDoS attacks is potentially much higher.

The report found that China, Germany, Russia and the US are playing host to the highest numbers of attack sources, with most attacks being directed towards Austria, Italy, the Netherlands, the UK, Ukraine and the US.

Tallying with Trend Micro’s findings, which showed Mirai is particularly dominant in the English-speaking underground, most Telnet traffic came from the US and the UK, alongside Germany and the Netherlands. Most SMB traffic, on the other hand, was found emanating from China, although this sort of data should always be taken with a pinch of salt because it is very easy, indeed normal, for attackers to route through proxies in other countries to avoid detection.

Source: https://www.computerweekly.com/news/252470509/Mirai-descendants-dominate-IoT-threat-environment

Last Friday, 7 September, Wikipedia suffered what appears to be the most disruptive Distributed Denial of Service (DDoS) attack in recent memory.

It’s not that Wikipedia isn’t attacked regularly – it is. It’s just that the DDoS that hit it around 17:40 p.m. (UTC) on that day was far larger than normal and carried on its attack for almost three days.

The site quickly became unavailable in Europe, Africa, and the Middle East, before later slowing or stopping for users in other parts of the world such as the US and Asia.

The size of the attack has not been made public, although from details offered by mitigation company ThousandEyes it’s clear that it was an old-style volumetric flood designed to overwhelm the company’s web servers with bogus HTTP traffic.

Given the protection sites employ these days, this suggests that it was well into the terabits-per-second range used to measure the largest DDoS events on the internet.

In fact, most of that flood would never have reached Wikipedia’s servers, instead of being thrown away by upstream ISPs as a protective measure when it became obvious that a DDoS was underway.

DDoS takedowns

An attack this big is sometimes called a ‘takedown’ (not be confused with legitimate takedowns connected to content), a relatively rare event intended to bring a well-known site’s operation to a halt for as long as possible.

Why Wikipedia? Most likely, because someone out there doesn’t like Wikipedia. As the site’s owners, Wikimedia, put it in a brief statement:

We condemn these sorts of attacks. They’re not just about taking Wikipedia offline. Takedown attacks threaten everyone’s fundamental rights to freely access and share information.

Less likely, a DDoS-for-hire outfit decided to use a famous site like Wikipedia as a look-what-we-can-do advert for their services at the considerable expense of revealing much of the botnet designed to host such attacks.

Given that the attack persisted into the weekend, it’s not surprising that Wikimedia called for help from Cloudflare, the zero-cost mitigation provider for sites that can claim to have a public purpose.

By Sunday, ThousandEyes noticed, Wikipedia’s servers were being ‘fronted’ entirely by Cloudflare, which deploys anti-DDoS technology to identify bad traffic and throw it away.

Interestingly, big DDoS takedowns have become somewhat less frequent these days, presumably because all sites that consider themselves targets employ mitigation companies to defend themselves.

But, at the very least, the Wikipedia attack is a warning that the people who carry out these attacks have not given up on trying.

Source: https://nakedsecurity.sophos.com/2019/09/11/wikipedia-fights-off-huge-ddos-attack/


Wikipedia, the seventh most popular website in the world, went offline in several countries on Friday because of a cyber attack.

Wikipedia Hit By DDOS Attack

The online encyclopedia confirmed that a malicious attack was behind outages of the site in Europe and some parts of the Middle East.

The attack appears to have started before 7 p.m. BST on Friday and left the site inaccessible to users in the UK, France, Germany, The Netherlands, Italy, and parts of the Middle East.

In a tweet, Wikipedia said the Wikimedia server of Wikimedia Foundation that hosts Wikipedia was paralyzed due to a massive Distributed Denial of Service (DDOS) attack. Wikimedia Foundation, the nonprofit organization behind Wikipedia, corroborated this in an official statement.

“Today, Wikipedia was hit with a malicious attack that has taken it offline in several countries for intermittent periods,” Wikimedia Foundation said. “We condemn these sorts of attacks. They’re not just about taking Wikipedia offline. Takedown attacks threaten everyone’s fundamental rights to freely access and share information.”

The attack was still ongoing when the statement was released on Friday, Sept. 7. Wikimedia Foundation said the Site Reliability Engineering team is still working to stop the attack and to restore access to the site.

DDOS Attack

A DDOS attack occurs when a server receives more access requests than it can handle, which disrupts its normal functioning and causes server performance to slow down, or eventually not able to work at all.

The botnets that try to access the website all at the same time can be composed of tens of thousands of computers that may have been compromised by hackers without the knowledge of their owners.


Wikipedia is one of the most popular websites based on Alexa’s ranking as of June 2019. It was initially an English language encyclopedia when it was launched in January 2001. Today, Wikipedia has more than 40 million articles in 301 different languages.

Source: https://www.techtimes.com/articles/245274/20190908/wikipedia-site-paralyzed-in-several-countries-due-to-massive-ddos-attack.htm