IT Pro is supported by its audience. When you purchase through links on our site, we may earn an affiliate commission. Learn more

Mirai 'botmasters' now exploiting Hadoop flaw to target Linux servers

Malware used to take half the internet offline is being used to build powerful botnets with just a handful of compromised servers

Botnet

Cyber criminals who used a botnet malware that took large parts of the internet offline in 2016 are now abusing Linux servers at scale.

Mirai, an open source malware, was conventionally used to target Internet of Things (IoT) devices like wireless cameras and routers. Malicious actors infamously used Mirai to construct a botnet that led to a devastating distributed denial of service (DDoS) attack against major online platforms.

But researchers have found evidence that certain strains are now targeting Linux servers, with a handful of attackers using custom tools to exploit a Hadoop YARN vulnerability and deliver malware instead of relying on bots to spread.

This is the first time security researchers have spotted non-IoT Mirai "in the wild", according to Network performance management firm Netscout.

"Mirai is no longer solely targeting IoT devices. While the techniques used to deliver Mirai to both IoT and Linux servers may be similar, it's much easier for attackers to attack the x86 monoculture of Linux servers than the wide array of CPUs used in IoT devices," said Netscout researcher Matthew Bing.

"The limited number of sources we've seen continually scanning for the Hadoop YARN vulnerability may indicate this activity is the work of a small group of attackers. Their goal is clear - to install the malware on as many devices as possible."

YARN (Yet Another Resource Negotiator) is a technology deployed as a resource management and job scheduling system for Apache Hadoop. It's responsible for allocating system resources to various applications running a Hadoop cluster, as well as scheduling tasks to execute on different nodes.

The vulnerability manifests as a command injection flaw that allows an attacker to execute arbitrary shell commands and resembles many flaws seen in IoT devices. It's for this reason Mirai attackers see Linux servers as a viable target.

His team's global network of 'honeypot' servers of recorded tens of thousands of attempts to exploit the vulnerability per day, indicating the flaw is being abused "at scale", with attackers sending exploits to as many vulnerable servers as they possibly can.

"Once gaining a foothold, Mirai on a Linux server behaves much like an IoT bot and begins brute-forcing telnet usernames and passwords," Bing continued.

"What's different now is that among the small, diminutive devices in the botnet lurk fully powered Linux servers."

Data centre-based Linux servers present a greater opportunity to launch DDoS attacks as they have more bandwidth than IoT devices, he explained, with attackers able to build a powerful botnet from just a handful of servers.

Mirai was behind one of the most disruptive DDoS attacks the world has sustained, with cyber criminals sending tens of millions of access requests to domain name system (DNS) provider Dyn from compromised IoT devices.

Dyn is used by a host of industry giants like Twitter, Spotify and Github to name a few, meaning all these services were taken offline when the DNS provider was targeted.

Featured Resources

Four strategies for building a hybrid workplace that works

All indications are that the future of work is hybrid, if it's not here already

Free webinar

The digital marketer’s guide to contextual insights and trends

How to use contextual intelligence to uncover new insights and inform strategies

Free Download

Ransomware and Microsoft 365 for business

What you need to know about reducing ransomware risk

Free Download

Building a modern strategy for analytics and machine learning success

Turning into business value

Free Download

Recommended

Hackers could use new Wslink malware in highly targeted cyber attacks
malware

Hackers could use new Wslink malware in highly targeted cyber attacks

1 Nov 2021
FBI raids Chinese POS business following cyber attack claims
malware

FBI raids Chinese POS business following cyber attack claims

27 Oct 2021
Malware developers create malformed code signatures to avoid detection
malware

Malware developers create malformed code signatures to avoid detection

24 Sep 2021
New malware uses search engine ads to target pirate gamers
malware

New malware uses search engine ads to target pirate gamers

21 Jul 2021

Most Popular

Russian hackers declare war on 10 countries after failed Eurovision DDoS attack
hacking

Russian hackers declare war on 10 countries after failed Eurovision DDoS attack

16 May 2022
Researchers demonstrate how to install malware on iPhone after it's switched off
Security

Researchers demonstrate how to install malware on iPhone after it's switched off

18 May 2022
Windows Server admins say latest Patch Tuesday broke authentication policies
Server & storage

Windows Server admins say latest Patch Tuesday broke authentication policies

12 May 2022