Malware borrows generously from code used by other botnets such as Mirai, Qbot and Zbot.
A rapidly evolving IoT malware dubbed “EnemyBot” is targeting content management systems (CMS), web servers and Android devices. Threat actor group “Keksec” is believed behind the distribution of the malware, according to researchers.
“Services such as VMware Workspace ONE, Adobe ColdFusion, WordPress, PHP Scriptcase and more are being targeted as well as IoT and Android devices,” reported AT&T Alien labs in a recent post. “The malware is rapidly adopting one-day vulnerabilities as part of its exploitation capabilities,” they added.
According to AT&T’s analysis of the malware‘s code base, EnemyBot borrows generously from code used by other botnets such as Mirai, Qbot and Zbot. The Keksec group distributes the malware by targeting Linux machines and IoT devices, this threat group was formed back in 2016 and includes several botnet actors.
The Alien lab research team study found four main sections of the malware.
The first section is a python script ‘cc7.py’, used to download all dependencies and compile the malware into different OS architectures (x86, ARM, macOS, OpenBSD, PowerPC, MIPS). After compilation, a batch file “update.sh” is created and used to spread the malware to vulnerable targets.
The second section is the main botnet source code, which includes all the other functionality of the malware excluding the main part and incorporates source codes of the various botnets that can combine to perform an attack.
The third module is obfuscation segment “hide.c” and is compiled and executed manually to encode /decode the malware strings. A simple swap table is used to hide strings and “each char is replaced with a corresponding char in the table” according to researchers.
The last segment includes a command-and-control (CC) component to receive vital actions and payloads from attackers.
AT&T researcher’s further analysis revealed a new scanner function to hunt vulnerable IP addresses and an “adb_infect” function that is used to attack Android devices.
ADB or Android Debug Bridge is a command-line tool that allows you to communicate with a device.
“In case an Android device is connected through USB, or Android emulator running on the machine, EnemyBot will try to infect it by executing shell command,” said the researcher.
“Keksec’s EnemyBot appears to be just starting to spread, however due to the authors’ rapid updates, this botnet has the potential to become a major threat for IoT devices and web servers,” the researchers added.
This Linux-based botnet EnemyBot was first discovered by Securonix in March 2022, and later in-depth analysis was done by Fortinet.
Vulnerabilities Currently Exploited by EnemyBot
The AT&T researchers release a list of vulnerabilities that are currently exploited by the Enemybot, some of them are not assigned a CVE yet.
The list includes Log4shell vulnerability (CVE-2021-44228, CVE-2021-45046), F5 BIG IP devices (CVE-2022-1388), and others. Some of the vulnerabilities were not assigned a CVE yet such as PHP Scriptcase and Adobe ColdFusion 11.
Log4shell vulnerability – CVE-2021-44228, CVE-2021-45046
F5 BIG IP devices – CVE-2022-1388
Spring Cloud Gateway – CVE-2022-22947
TOTOLink A3000RU wireless router – CVE-2022-25075
Kramer VIAWare – CVE-2021-35064
“This indicates that the Keksec group is well resourced and that the group has developed the malware to take advantage of vulnerabilities before they are patched, thus increasing the speed and scale at which it can spread,” the researcher explained.
The Alien lab researcher suggests methods to protect from the exploitation. Users are advised to use a properly configured firewall and focus on reducing Linux server and IOT devices’ exposure to the internet.
Another action recommended is to monitor the network traffic, scan the outbound ports and look for the suspicious bandwidth usage. Software should be updated automatically and patched with the latest security update.