Mirai Is Evolving as a DDoS Attack Tool

Mirai, the malware that nearly brought down the internet, is evolving and being refined by cybercriminals as a distributed denial of service (DDoS) attack tool.

Symantec’s Principal Threat Analysis Engineer Dinesh Venkatesan recently disclosed that he uncovered multiple Mirai variants. Venkatesan said that these multiple Mirai variants are hosted in a live remote server.

Each of these Mirai variants is described to be aimed for a particular platform, making the Mirai portable across different platforms.

According to Venkatesan, one of the major obstacles encountered by script-kiddies, also known as copy/paste malware authors, is portability – the ability of a malware to run on different platforms “in a self-contained capsule without any runtime surprises or misconfiguration”.

The newly uncovered Mirai variants found an answer to the problem of portability by leveraging on the open source tool called “Aboriginal Linux”. According to the author of Aboriginal Linux, this open source tool “automatically create cross compilers and bootable system images for various targets, such as arm, mips, powerpc, and x86”.

Using the Aboriginal Linux, the author or authors of the newly uncovered Mirai variants were able to develop versions of the malware tailored for a targeted platform, ranging from routers, IP cameras and even Android devices.

Symantec’s Venkatesan said that the newly uncovered Mirai variants spread by scanning devices with default factory login details or known security vulnerabilities.

Original Mirai Botnet

In December last year, 21-year old Paras Jha, along with his two college-age friends Josiah White and Dalton Norman, pleaded guilty for creating the Mirai botnet.

According to the U.S. Department of Justice, in the summer and fall of 2016, Jha, White and Norman created and launched the Mirai botnet – referring to computers infected by the Mirai malware and controlled by Jha’s group without the knowledge or permission of the owners of the computers.

The U.S. Department of Justice said the trio used the Mirai botnet, which at its peak consisted of hundreds of thousands of compromised IoT devices, to launch DDoS attacks.

DDoS attacks refer to cyberattacks which use multiple computers (like the Mirai botnet), controlling these computers without the computers’ owners knowledge for the purpose of making an online service unavailable by overwhelming it with traffic.

“The defendants [Jha, White and Norman] used the botnet to conduct a number of powerful distributed denial-of-service, or ‘DDOS’ attacks, which occur when multiple computers, acting in unison, flood the Internet connection of a targeted computer or computers,” the U.S. Department of Justice said.

While the latest Mirai variants infect not just IoT devices but also Android devices, the computers infected by the original Mirai malware were limited to IoT devices, including routers, wireless cameras, digital video and recorders.

According to the U.S. Department of Justice, the trio’s involvement with the original Mirai ended when Jha posted the source code of Mirai on an online forum in September 2016. “Since then, other criminal actors have used Mirai variants in a variety of other attacks,” the U.S. Department of Justice said.

Jha’s group was able to infect hundreds of thousands of IoT devices with the Mirai malware and turned it into a botnet or zombie army for DDoS attacks by using a short list of 62 common default usernames and passwords.

In October 2016, the DDoS attack against the internet infrastructure company Dynbrought down a big part of the internet on the U.S. east coast. The DDoS attack against Dyn made the world’s top websites, such as Amazon, Twitter and Netflix, temporarily inaccessible. “We are able to confirm that a significant volume of attack traffic originated from Mirai-based botnets,” Dyn said in a statement.

Other Mirai Variants

Early variants of Mirai include Satori, a Mirai variant that morphed into several versions as well. One version of Satori targets Huawei home router HG532. Satori was first observed in the wild by Check Pointresearchers in November 2017. Similar to the original Mirai, Satori has DDoS capabilities and has been reported to launch several DDoS attacks.

According to Check Point, Huawei was informed prior to the public disclosure of Satori. Before the public disclosure of Satori as well Huawei patched the vulnerability.

In May 2018, researchers at FortiGuard Labsuncovered another variant of Mirai called “Wicked”. This Mirai variant particularly infects Netgear routers and CCTV-DVR devices.

According to FortiGuard Labs, Wicked infects Netgear routers and CCTV-DVR devices by using known and available cyberexploits, many of them are old exploits. Similar to the original Mirai and other Mirai variants, Wicked can also be used for DDoS attacks.

Prevention

Here are some measures in preventing attackers from turning your organization’s IoT devices into a zombie soldier for DDoS attacks:

-Change default login details into something strong and unique

-Install firmware updates in a timely manner

-When setting up Wi-Fi network access, use a strong encryption method

-Use wired connections instead of wireless connections

-Disable the following:

  1. Features and services that aren’t used
  2. Telnet login (use SSH instead)
  3. Universal Plug and Play (UPnP)
  4. Remote access

If your organization has an online presence, it’s imperative that your organization is equipped in stopping DDoS attacks.

A successful DDoS attack against your organization’s online service negatively impacts your organization’s reputation, can cause loss of customer trust and financial losses. Prolong and unmitigated DDoS attacks can also result in permanent business closure.

Contact us today if you need assistance in securing your organization’s online services from DDoS attacks and if your organization needs assistance in securing IoT devices from being turned into zombie devices for DDoS attacks.