Pierluigi Paganini December 25, 2019

A new Mozi P2P botnet is actively targeting Netgear, D-Link, and Huawei routers by probing for weak Telnet passwords to compromise them.

Security experts from 360 Netlab spotted a new Mozi P2P botnet that is actively targeting Netgear, D-Link, and Huawei routers by probing for weak Telnet passwords to compromise them.

According to the researchers, in the last months, the botnet was mainly involved in DDoS attacks, experts also noticed that the sample borrows part of code from the Gafgyt malware.

The botnet implements a custom extended Distributed Hash Table (DHT) protocol that provides a lookup service similar to a hash table ([key, value]).

“Mozi Botnet relies on the DHT protocol to build a P2P network, and uses ECDSA384 and the xor algorithm to ensure the integrity and security of its components and P2P network.” reads the analysis published by the experts. “The sample spreads via Telnet with weak passwords and some known exploits (see the list below). In terms of functions, the execution of the instructions of each node in the Mozi botnet is driven by a Payload called Config issued by the Botnet Master.”

This kind of implementation makes it simple to add/remove nodes with minimum workaround re- keys.

The Mozi Botnet uses its own implementation of the extended DHT protocol to build a P2P network.

The malware spreads by attempting to guess Telnet passwords of target devices and leveraging known exploits. Once gained access to the device, the bot attempt to execute a malicious payload and the bot will automatically join the Mozi P2P network.

The botnet supports implements the following capabilities:

• DDoS attack
• Collecting Bot Information
• Execute the payload of the specified URL
• Update the sample from the specified URL
• Execute system or custom commands

“After Mozi establishes the p2p network through the DHT protocol, the config file is synchronized, and the corresponding tasks are started according to the instructions in the config file,” continues the analysis.

In order to avoid the botnet takeover by security experts or law enforcement agencies networks, the Mozi botnet implements a signature verification on each synchronized config.

Nodes belonging to the Mozi P2P botnet only accept commands that pass the verification process. The main commands implemented by Mozi bot allow it to:

• Launch DDoS attacks (this module reuses Gafgyt’s attack code, supports HTTP, TCP, UDP, and other attacks)
• Collect and exfiltrate bot info (Bot ID, IP, PORT, filename (full path), gateway, CPU architecture)
• Execute payload from URL
• Update from the specified URL
• Execute system or bot custom commandsOpen Energy di Enel EnergiaAd by ENELSee More

The bot targets the following devices:

Additional information on the Mozi P2P botnet, including IoCs, are available in the Netlab report. 

Pierluigi Paganini

(SecurityAffairs – Mozi botnet, malware)

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