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DDoS Extortions Return
Over the past few weeks, a group of cybercriminals has launched distributed denial-of-service (DDoS) attacks targeting companies in the finance and retail sectors and demanding ransom payment for the attacks to stop.
In the blog post "Ransom Demands Return: New DDoS Extortion Threats From Old Actors Targeting Finance and Retail", Akamai reported that over the past few weeks, a series of DDoS attacks from the so-called "Armada Collective" and "Fancy Bear" actors have targeted businesses across multiple sectors, including finance and retail, and these DDoS attacks come with extortion demands. Some of the attacks peaked at almost 200 gigabyte per second (GB/s), Akamai said.
ZDNet likewise reported that in the past weeks, a criminal group that goes with the names "Armada Collective" and "Fancy Bear" has launched DDoS attacks against some of the biggest financial service providers and demanded payments in the form of the cryptocurrency bitcoin as extortion fees to stop the DDoS attacks.
Incidentally, a few days ago, the operations of the New Zealand stock exchange were disrupted as a result of a DDoS attack. Other than the comment that the attack came from overseas, authorities in New Zealand won't comment on whether or not the DDoS attack also involved a ransom demand.
Evolution of DDoS Extortions
DDoS extortion is nothing new. This type of extortion has been around in the last few years. The recent DDoS extortions, however, differ with the older DDoS extortions in terms of methods and severity.
The recent DDoS extortion campaign described by Akamai and ZDNet resembled that the type of DDoS extortion campaign described in the alert entitled "DDoS extortion campaign targeting financial sector" released on November 1, 2019 by the Computer Emergency Response Team New Zealand (CERT NZ).
According to CERT NZ, it received reports relating to a DDoS extortion campaign targeting companies within the financial sector in New Zealand. This extortion campaign had also been observed in other countries, CERT NZ said. As described by CERT NZ, the DDoS extortion campaign followed these steps:
First, the target company receives an email stating “We are the Fancy Bear and we have chosen [Company Name] as a target for our next DDoS attack.” In the email, the attackers give the target company a deadline when the major DDoS will happen and demand from the target ransom to prevent the said major DDoS attack.
Second, to threaten the target that the major DDoS attack is coming, a minor DDoS is launched against an IP address belonging to the company's network. These demo attacks generally last for 30 minutes.
In the DDoS extortion campaign observed by Akamai, the targets were warned that going public about the extortion demand will result in the immediate major DDoS attack. The extortion demand also threatens the targets that the major attack will make websites and other connected services "unavailable for everyone" and will harm the target's reputation.
While past DDoS extortion campaigns targeted the victims' websites, the recent extortion campaign described by CERT NZ, Akamai and ZDNet targeted the victims' backend infrastructure, resulting in prolonged and severe outages. An example of a backend infrastructure is the DDoS attack on the target's web hosting provider resulting in the outages of the ultimate target's website.
In the case of the attack of the New Zealand stock exchange, the stock exchange's web hosting provider Spark was targeted in a series of DDoS attacks, resulting in the outages at the New Zealand stock exchange as well as downtime of the websites of Spark's other customers.
Reflective DDoS Techniques
In the November 2019 alert, the CERT NZ said that the so-called Fancy Bear threat group overwhelms the target using a variety of reflective DDoS techniques, with targets including services using the following protocols:
A reflective DDoS technique is a DDoS attack that depends on publicly accessible UDP servers to overwhelm a victim’s system with UDP traffic. UDP, short for User Datagram Protocol, is an internet communication protocol for time-sensitive transmissions such as video chat. UDP is designed not to validate source Internet Protocol (IP) addresses for the protocol to operate very quickly. This, however, creates an exploitation opportunity for attackers.
In general, in a reflective DDoS attack, an attacker who’s capable to spoof IP addresses sends fake requests to a vulnerable UDP server. The UDP server, not knowing the request is fake, prepares the response. These UDP responses are delivered to an unsuspecting target, overwhelming the target’s resources such as the network itself.
Best Practices Against DDoS Extortions
It’s recommended not to pay ransom to DDoS extortionists. Ransom payment only encourages extortionists to attack your organization again.
Like any other types of DDoS attacks, in DDoS attacks using reflective techniques, two groups are exploited by the attackers: the ultimate target and vulnerable computers, in this case, vulnerable UDP servers. In order to prevent your organization’s computers from being used for reflective DDoS attacks, it’s best to stop using UDP when not needed. If UDP is needed, configure it to always respond with smaller packet size. It’s also important to use a Firewall.
To protect your organization from being the ultimate target of a reflective DDoS attack, it’s best to work with your trusted cybersecurity service provider and use a DDoS protection service to prevent the DDoS traffic from reaching your organization’s systems.
The Driz Group specialized in DDoS protection and can mitigate the DDoS attack in just a few minutes.
Steve E. Driz, I.S.P., ITCP