This is the last part of the blog series exploring the various alternatives for protection against DDoS attacks, and how to choose the optimal solution for you. The first part of this series covered premise-based hardware solutions, the second part discussed on-demand cloud solutions, and the third part covered always-on cloud solutions. This final piece will explore hybrid DDoS solutions, which combine both hardware and cloud-based components.
This blog series dives into the different DDoS protection models, in order to help customers choose the optimal protection for their particular use-case. The first parts of this series covered premise-based appliances and on-demand cloud services. This installment will cover always-on cloud DDoS protection deployments, its advantages and drawbacks, and what use-cases are best for it. The final part of this series will focus on hybrid deployments, which combine premise-based and cloud-based protections.
This blog series explores the various options for DDoS protection and help organizations choose the optimal solution for themselves. The first part of this series covered the premise-based DDoS mitigation appliance. This installment will provide an overview of on-demand cloud-based solutions. Subsequent chapters will also cover always-on and hybrid solutions.
Let’s take a journey through a real-life booter and stresser service to better understand the tools, the trade and pricing behind DDoS-as-a-Service.
A question that I’ve encountered many times in the field of late is what are the impacts of DDoS attacks on cloud compute environments? The primary benefit of cloud is that it elastically scales to meet variable demand, scale up instantly, scale down when demand subsides – in seconds… So layman’s logic might say that cloud-based services are immune from the downtime effects of DDoS attackers, however the possibility of gigantic unexpected bills is a given?
On February 8th, 2018, Radware’s Deception Network detected a significant increase in malicious activity over port 8080. Further investigation uncovered a new variant of the Satori botnet capable of aggressive scanning and exploitation of CVE-2017-18046 – Dasan Unauthenticated Remote Code Execution. Referred to as “Satori.Dasan,” it’s been rapidly expanding with a high success rate. The C2/Exploit server for this botnet is 188.8.131.52 (AS49349 – BlazingFast LLC, Ukraine)
It is not clear what is the purpose of this new botnet, as we were unable to find specific attack vectors in the binary.
Our analysis suggests that Satori is looking to take over 40,000 IoT devices to join its growing family of cryptocurrency miners, as we saw here, and here. This would make the Satori.dasan malware a stage #1 infection, responsible for rapidly scanning the internet looking for vulnerable devices.
Over the past two days Radware has detected over 2000 malicious Unique IPs daily, almost 10 times higher than the daily average in the weeks prior.
The majority of the traffic came from Vietnam originating almost entirely from an ISP named ‘Viettel.’
A significant percentage of those malicious bots were also listening themselves on port 8080.
By sampling roughly 1000 IPs and querying their server headers, Radware revealed that 95% identified themselves as running “Dasan Network Solution.”
A quick Shodan search revealed about 40,000 devices listening on port 8080, with over half located in Vietnam, and not surprisingly an ISP named ‘Viettell Corporation.’
Botnet Activity: Distributed Scanning and Central Exploitation Server
The infected bots will perform aggressive scanning of random IP addresses, exclusively targeting port 8080. Once it finds a suitable target, it notifies a C2 server which immediately attempts to infect it.
See the following sequence captured at one of Radware’s sensors (10.0.0.70):
The infected bot sends a half-open stealth-scan SYN request to port 8080. Instead of Ack, a TCP Reset is sent. Typical to Mirai code, the initial TCP SYN packet contains a sequence number identical to the 32bit value of the target victim.
After 4 seconds, the bot establishes a 3-way TCP handshake to port 8080
The following 113 bytes payload is sent:
Note that this is not the actual exploitation attempt, but rather a screening process to find vulnerable hosts.
Radware’s Deception Network sensor is answering the probe with the following response:
The bot closes the connection.
Now comes the interesting part.
Notice the timestamp – it is just 106 milliseconds after the last packet and we suddenly get an exploitation attempt from a completely different IP address. This IP belongs to a central exploitation server running on 184.108.40.206
The exploit server sends the following payload over HTTPS port 8080:
Investigating the Malware
With some scanning, fuzzing and Open-Source Intelligence (OSINT0) we found some interesting details.
As with previous incidents, the domain rippr.me is used to point to the C2 server.
The following entries have an associated TXT record:
As we saw in the exploit payload, the server is listening on port 7777. Connecting to it brings the following download code:
So let’s get the file and check the contents:
It looks like a downloader that will be running on an infected device. The script downloads several versions of the binary and tries to execute it. If it fails (due to wrong CPU architecture), it will just go over to the next one.
Let’s grab the binaries (and guess some additional ones, like the x86_64). They look quite fresh according to server timestamps:
At the moment, VirusTotal already knows about the C2 address and shows that less than five antivirus products detect the files as malicious. Not very promising right now, but this should improve.
We will use this opportunity to submit some of the binaries that are missing in VT.
The Satori.Dasan variant is a rapidly growing botnet which utilizes a worm-like scanning mechanism, where every infected host looks for more hosts to infect. In addition, it also has a central C2 server that handles the exploitation itself once the scanners detect a new victim.
Read “2017-2018 Global Application & Network Security Report” to learn more.
There is a great scene in the movie Victor, Victoria, where the character played by James Garner decides it’s time to mix things up a bit. So, he strolls into an old gritty bar wearing a tuxedo, walks up to the bartender, and orders milk. Within minutes, the other men in the bar decide they’ve had enough of this, and they start an intense bar fight. Garner is soon throwing and taking punches, getting tossed across the floor, and loving every minute of it.
In the past five years, we have watched a rapid evolution in both sophistication and scale of DDoS attacks. Long gone are the days of the traditional Denial of Service (DoS) attack. Now, threat actors use massive IoT botnets to enslave millions of devices into global scale DDoS attacks. They confuse defenses by launching short multi-vector attacks in bursts, they multiply the force impact of their attacks by using TLS/SSL, and even destroy systems with Permanent Denial of Service (PDoS) attacks.
Thoughts from Radware’s Global Application and Network Security Report
- Rise of cryptocurrency trade and value boosts attacks;
- Notorious attacks of the year point at the human factor to blame;
- Machine-learning technologies are not fully mature nor broadly adopted;
- Despite a notion of tolerance, in one of four cases customers will take action against a targeted organization;
- IoT devices power more effective DDoS attacks, but nobody takes responsibility to patch the known holes;
- Data Leakage is the number one concern of organizations today.
These are just a handful of insights from Radware’s 2017-2018 Global Application and Network Security Report, providing a comprehensive view of the industry trends and evolutions. 2017 was an eventful year, with global cyber-attack campaigns that grabbed headlines in mainstream media and affected the lives of many, in particular the WannaCry, NotPetya and BadRabbit ransom sprees, as well as Equifax and Forever 21 data leaks. Let’s take a closer look at 2017 trends and 2018 predictions:
2017 has been another eventful year for denial-of-service attacks. Radware’s ERT team has monitored a vast number of events, giving me ample opportunities to review and analyze attack patterns to gain further insight into trends and changes in the attack vector landscape. Here is some insight into what we have observed: