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 //

Malware

4/17/2019
01:10 PM
Larry Loeb
Larry Loeb
Larry Loeb
50%
50%

Servers Discovered With Multiple Malware Families, Staged & Ready to Launch

Bromium has uncovered US-based web servers that are being used to host and distribute these kinds of malware including banking trojans, information stealers and ransomware.

You're a wizened cyber criminal, used to buying exploits from dark websites so that you can unleash upon an unsuspecting populace your nefarious schemes and gain untold profits.

But there's one practical problem. You have to stash the malware somewhere, and then make it appear when you are ready to slash and burn.

Bromium has uncovered US-based web servers that are being used to host and distribute these kinds of malware including banking trojans, information stealers and ransomware.

They found that between May 2018 and March 2019 showed threats like these were originating from web-servers registered under the name PONYNET. This was found to be hosted on BuyVM data centers in Las Vegas, Nevada. Lastly, BuyVM is owned by FranTech solutions, a so-called "bulletproof hosting provider" which has links to far-right websites like the Nazi site the Daily Stormer.

The New Yorker magazine has an interesting profile about FranTech and Francisco Dias, the founder of FranTech and two affiliated companies, BuyVM and Buyshared. BuyVM sells virtual private server (VPS) hosting services and is located in Las Vegas, NV. Bromium says that Dridex, Gootkit, IcedID, Nymaim, Trickbot, Fareit, Neutrino, AZORult, Gandcrab and Hermes have all been traced back to the FranTech websites.

The Bromium blog notes that multiple malware families were staged on the same web servers and subsequently distributed through mass phishing campaigns. Now, reusing the servers to host different malware indicates the involvement of a common element in the activities of different malware operators. The variety of malware families hosted, and the apparent separation of command and control (C2) from email and hosting infrastructure, suggests the existence of distinct threat actors: one responsible for email and hosting and others in charge of operating the malware.

The servers Bromism identified were found to be using similar software builds, default installations of CentOS and Apache HTTP Server versions 2.4.6 or 2.2.15. The malicious executables that were found were nearly always hosted in their root directory.

Traces of these servers were also found in the attack vectors. Nearly all of the campaigns delivered phishing emails with Microsoft Word documents that contained malicious VBA macros. The emails and infected documents used in the campaigns were all English and targeted US companies -- 42% of infected documents claimed to be job applications or CVs and a further 21% posed as unpaid invoices The phishing emails also contained a hyperlink to a domain which pointed to one of the malware distribution servers. A deep analysis of the macros that were used in the Word droppers found that they all contained a hard-coded IP address of the web server hosting the second-stage malware used in the attack, rather than a domain name. Multiple malware families were found to be hosted on the same server, or could be used in conjunction with each other where one would act as a dropper for the other.

Bromism saw this in July and August 2018 campaigns that delivered AZORult, an information stealer. That, in turn, downloaded the Hermes ransomware. Both types of malware were hosted on the same server.

One unusual aspect to all of this is that the web server enforced HTTP basic authentication as a means of preventing the executable from being downloaded without a correct username and password. It is likely that this was implemented to impede investigations by network defenders and researchers because analysis of the payload requires access to the Word dropper or sources of network traffic containing the HTTP request, such as proxy logs or full packet capture.

— 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...