Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

ABTV

12/24/2019
12:18 PM
Larry Loeb
Larry Loeb
Larry Loeb
50%
50%

New Botnet Uses DHT as Its Foundation

Security researchers at 360 Netlab have been watching a new botnet they call Mozi for the last four months. It's a new P2P botnet with implementation that is based on the Distributed Hash Table protocol.

Security researchers at 360 Netlab have been watching a new botnet they call Mozi (from one of the internal files) for the last four months. It's a new P2P botnet with implementation that is based on the Distributed Hash Table (DHT) protocol.

The researchers also say in their post announcing the discovery that "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. The sample spreads via Telnet with weak passwords and some known exploits." They found that Netgear, D-Link and Huawei routers were easy targets for Mozi.

The DHT protocol used is based on the standard commonly used by torrent clients, but the hash table itself is a custom one. The DHT that is used in creating the botnet's network means that it is done without needing to use servers. It is also much easier to hide the botnet's payload in the large amount of normal DHT traffic, which makes detection of its origins harder than it otherwise might be.

Netlab also says the bot "does reuse part of the Gafgyt code, but it is not really Gafgyt."

The main commands available to the bot include a DDoS attack, collecting information, executing the payload of the specified URL, updating from a specified URL and executing system or custom commands.

The malware first seeks to establish a beachhead by opportunistically exploiting weak or known telnet passwords, such as might be found on a CCTV device or some other IoT mechanism. It starts an http session and then receives the sample download address in the Config file used by Mozi, which is issued by the Botnet Master. Next, it writes the downloader file in echo mode and runs it.

The infected device will run the bot code and then joins the Mozi network, announcing itself as a new node. It will not be a trusted node of the network until it can pass the signature verification routine. Then it will be accepted and used by the Mozi node for nefarious purposes.

As a last step, it looks for other devices to infect. It depends on certain vulnerabilities to extend itself. The blog posts a list of the affected devices, which includes the Eir D1000 Router, Vacron NVR devices, devices using the Realtek SDK (for the CVE-2014-8361 vuln), Netgear R7000 and R6400, DGN1000 Netgear routers, MVPower DVR, Huawei Router HG532 (for CVE-2017-17215), D-Link Devices and GPON Routers.

Netlabs is somewhat vague on mediation. They say to "update the patch in a timely manner, and determine whether they are infected by looking up the process and file name, and HTTP, DHT network connection characteristics created by Mozi Botnet." This seems to mean hand-tweaking of all networks possibly exposed.

As more information about the botnet emerges, tools will no doubt be developed to help in the mediation.

— Larry Loeb has written for many of the last century's major "dead tree" computer magazines, having been, among other things, a consulting editor for BYTE magazine and senior editor for the launch of WebWeek.

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
COVID-19: Latest Security News & Commentary
Dark Reading Staff 9/25/2020
Hacking Yourself: Marie Moe and Pacemaker Security
Gary McGraw Ph.D., Co-founder Berryville Institute of Machine Learning,  9/21/2020
Startup Aims to Map and Track All the IT and Security Things
Kelly Jackson Higgins, Executive Editor at Dark Reading,  9/22/2020
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
Special Report: Computing's New Normal
This special report examines how IT security organizations have adapted to the "new normal" of computing and what the long-term effects will be. Read it and get a unique set of perspectives on issues ranging from new threats & vulnerabilities as a result of remote working to how enterprise security strategy will be affected long term.
Flash Poll
How IT Security Organizations are Attacking the Cybersecurity Problem
How IT Security Organizations are Attacking the Cybersecurity Problem
The COVID-19 pandemic turned the world -- and enterprise computing -- on end. Here's a look at how cybersecurity teams are retrenching their defense strategies, rebuilding their teams, and selecting new technologies to stop the oncoming rise of online attacks.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2020-15208
PUBLISHED: 2020-09-25
In tensorflow-lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, when determining the common dimension size of two tensors, TFLite uses a `DCHECK` which is no-op outside of debug compilation modes. Since the function always returns the dimension of the first tensor, malicious attackers can ...
CVE-2020-15209
PUBLISHED: 2020-09-25
In tensorflow-lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, a crafted TFLite model can force a node to have as input a tensor backed by a `nullptr` buffer. This can be achieved by changing a buffer index in the flatbuffer serialization to convert a read-only tensor to a read-write one....
CVE-2020-15210
PUBLISHED: 2020-09-25
In tensorflow-lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, if a TFLite saved model uses the same tensor as both input and output of an operator, then, depending on the operator, we can observe a segmentation fault or just memory corruption. We have patched the issue in d58c96946b and ...
CVE-2020-15211
PUBLISHED: 2020-09-25
In TensorFlow Lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, saved models in the flatbuffer format use a double indexing scheme: a model has a set of subgraphs, each subgraph has a set of operators and each operator has a set of input/output tensors. The flatbuffer format uses indices f...
CVE-2020-15212
PUBLISHED: 2020-09-25
In TensorFlow Lite before versions 2.2.1 and 2.3.1, models using segment sum can trigger writes outside of bounds of heap allocated buffers by inserting negative elements in the segment ids tensor. Users having access to `segment_ids_data` can alter `output_index` and then write to outside of `outpu...