Security researchers discovered a new variant of Mirai malware known as Miori that is targeting internet of things (IoT) devices to integrate into a larger botnet and launch distributed denial-of-service (DDoS) attacks.

Trend Micro noted that the threat, which was first identified in early December, takes advantage of an exploit in the ThinkPHP programming framework. The remote code execution (RCE) vulnerability allows threat actors to infect machines based on the Linux operating system and execute Miori, which then generates a notification on the victim’s console.

Once attackers verify that a system has been infected through their command-and-control (C&C) server, they utilize the Telnet protocol and take advantage of weak or commonly used passwords to conduct brute-force attacks on other IP addresses. In a screenshot, researchers looking into Miori revealed some of the passwords that were used during recent attack campaigns, which included admin123, support, root and even default.

Miori Is Just the Latest in the Mirai Malware Family

Researchers noted that Miori is just one of many variations of Mirai discovered since the original malware made its debut. In September 2016, for example, millions of users temporarily lost internet access after the malware targeted Dyn, which provides a significant portion of the internet’s backbone. Similar attacks based on Mirai have been launched against major telecommunications operators in Germany and the U.K. over the past few months.

Besides Miori, other Mirai offspring include Shinoa, APEP and IZ1H9, which use the same RCE exploit to find and infiltrate victims’ open source-based machines.

How to Defend Against Miori, Mirai and More

Given the many different versions of Mirai, coupled with the growing number of IoT devices in offices and homes, organizations can no longer afford to employ weak password protection in 2019. As security experts have noted, some threat actors even take advantage of password databases called dumps, which collect commonly used credentials to make the work of attackers even easier.

Besides regularly updating passwords, organizations should also think about requiring passwords that are 12 characters or longer, rather than the typical eight characters. Backing up passwords, using a password manager and utilizing multifactor authentication (MFA) tools that add an additional layer of security onto connected devices can also help defend against emerging threats.

Sources: Trend Micro, Wired