Mirai Botnet Operator Responsible for Cutting Off Internet Access of an Entire Country Jailed

A UK court recently sentenced to 2 years and 8 months 30-year-old Daniel Kaye for operating the Mirai botnet, which resulted in cutting off the internet access of the entire country of Liberia.

Kaye pleaded guilty in carrying out intermittent Distributed Denial of Service (DDoS) attacks on the Liberian telecommunications provider Lonestar MTN. According to Kaye, he was hired by a rival Liberian network provider and paid a monthly retainer to conduct intermittent DDoS attacks on Lonestar.

According to theUK National Crime Agency (NCA), from September 2016, Kaye started operating his own Mirai botnet, composed of a network of infected Dahua security cameras, to carry out intermittent DDoS attacks on Lonestar. In November 2016, the NCA said that the traffic from Kaye’s Mirai botnet was so high in volume that it disabled internet access all over Liberia.

The intermittent DDoS attacks on Lonestar, the NCA added, resulted in revenue loss of tens of millions in US dollars as customers left the network, and cost the company approximately 600,000 USD for remedial cost to prevent the attacks from happening again.

What Is a Mirai Botnet?

Mirai is a malicious software (malware) that infects Internet of Things (IoT) devices, such as video cameras, and turns these infected IoT devices into a botnet – referring to a group of infected computers that’s operated under the control of a cybercriminal to conduct malicious activities such as DDoS attacks.

Mirai first came to public attention on September 20, 2016, when it attacked Brian Krebs’ security blog. The DDoS attack on Krebs’ security blog was considered one of the largest on record at the time. By the end of September 2016, just days after the DDoS attack on Krebs’ security blog, the author of Mirai, using the name “Anna Senpai”, released the source code of Mirai on an online hacking forum. Anna Senpai claimed that 380,000 IoT devices had been infected by the Mirai malware and formed part of the botnet that took down Krebs’ website.

The Mirai source code reveals that this malware continuously scans the internet for IoT devices that use any of the 61-factory default username and password combinations. While 62 username and password combinations are listed on the Mirai source code, there’s one duplication, leaving only 61 unique username and password combinations. 

Given that many owners of IoT devices didn’t bother to change factory default usernames and passwords combinations, the Mirai malware easily infected hundreds of thousands of IoT devices and turned them as a botnet for DDoS attacks.

The publication of the Mirai source code on an online forum encouraged other cybercriminals to copy the code and operate their respective Mirai botnets. Following the publication of the Mirai source code, a series of high-profile DDoS attacks were attributed to Mirai botnets.

On October 21, 2016, Mirai brought down a big chunk of the internet on the U.S. east coast. Dyn, an internet infrastructure company, was a subject a DDoS attack that subsequently rendered popular websites inaccessible to the public. Dyn, in a statement, said that a significant volume of DDoS attack traffic originated from Mirai botnets. To date, the perpetrator of the Dyn DDoS attack remains unknown and no case has been filed against anyone in relation to this attack.

In addition to Lonestar DDoS attacks, Kaye also admitted to launching DDoS attacks using his own Mirai botnet on Deutsche Telekom that affected 1 million customers in November 2016. Kaye was extradited to Germany for this crime but only received a suspended sentence.

Three college-age friends in late 2017, Paras Jha, Josiah White and Dalton Norman, pleaded guilty before a U.S. court in creating the Mirai malware. Jha, in particular, pleaded guilty in launching multiple DDoS attacks using Mirai on Rutgers University computer system, resulting in the shutting of the University’s server used for all communications among faculty, staff and students.

Jha, White and Norman dodged jail. Jha, in particular, was ordered by a New Jersey court to pay $8.6 million in restitution and serve 6 months of home incarceration for launching DDoS attacks on the Rutgers University computer network.

The U.S. Department of Justice, in a statement, said that Jha, White and Norman’s involvement with the Mirai ended when Jha posted the Mirai source code on an online forum. “Since then, other criminal actors have used Mirai variants in a variety of other attacks,” the U.S. Department of Justice said.

Prevention

The publication of a source code of a malware has two sides. First, it encourages script kiddies – those who attempt to launch cyberattacks using scripts or codes written by others, such as in the case of Mirai. Many script kiddies, using the original Mirai source code, have been able to build their own DDoS botnets and offer the service called “DDoS-for-hire”.

Second, the flipside of making a malware source code public is that this enables the cybersecurity community to study the code and develop tools and advisories that could render this malware inoperable or useless.

There are currently available security tools that block DDoS attacks coming from Mirai botnets. Also, a simple change of factory default username and password combinations can prevent IoT devices from being infected by the Mirai malware and, in effect, could prevent DDoS attacks.

Cybercriminals are, however, relentless in their campaigns. Since the publication of the Mirai source code, cybercriminals have tweaked the Mirai source code, for instance, infecting not just IoT devices, but enterprise servers as well. Attackers also don’t simply use factory default login details in infecting computer devices, but also exploit known security vulnerabilities.