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.

Threat Intelligence

10/2/2019
12:40 PM
50%
50%

MasterMana Botnet Shows Trouble Comes at Low Cost

For less than $200, attackers were able to infect thousands of systems, stealing user credentials, cryptocurrency wallets, and web histories, an analysis finds.

A cybercrime campaign that starts with phishing, uses Bit.ly and Pastebin to pass commands, and results in the theft of the victim's user credentials, cryptocurrency wallets, and web history may have cost as little as $160 to run and likely infected thousands of systems every week, according to two researchers with security firm Prevailion.

The campaign, which the firm calls the MasterMana botnet, keeps costs down by hosting it on a single virtual private server and using public services as drop boxes for documents that contain encrypted commands, according to the firm's October 2 analysis. The attack highlights the asymmetry between attackers and defenders — with a few hundred dollars, attackers can breach defenses that may cost hundreds of thousands or millions of dollars annually, says Danny Adamitis, director of intelligence for Prevailion.

"When it came down to monetary cost, the only thing that these actors were paying for was the $100 for one Trojan and the $60 a month for a virtual private server from one particular provider," Adamitis says. "You can cause so much mayhem for so little money."

While a great deal of industry focus is on opportunistic attacks that could potentially affect hundreds of thousands of systems, or targeted attacks that home in on a few dozen victims, the bargain-basement infrastructure used by MasterMana shows that even small-time attacks can be a worry for companies if they're conducted by relatively skilled attackers, Adamitis says.

In their analysis of the botnet, Prevailion's researchers argued that the balance between sophistication and low-cost techniques hit a sweet spot that many advanced persistent threats (APTs) miss. The attack is "sophisticated enough to avoid automated detection through third-party services and obfuscation, while remaining below APT-level sophistication to avoid drawing attention to their campaign," Adamitis and Adam Flatley, vice president of tailored intelligence, wrote in the analysis.

The attack starts with phishing e-mails requesting information about the targeted company's products. While the e-mail messages are not very well constructed, thousands of victims have apparently opened the attached Microsoft Excel file. If the victim opens the attachment, either a macro will run and connect to Bit.ly or, in another case, the attackers used a vulnerability from 2017. While Prevailion did not see other file formats used in the attack, the company has seen other analyses citing malicious documents in Microsoft's other file formats, including Word, PowerPoint, and Publisher.

The Bit.ly link led to a Blogspot page, which then ran malicious JavaScript code that, in turn, downloaded and ran code from Pastebin. The multiple redirections make it harder to analyze the code and automatically assess whether the application is malicious, Adamitis says. The code created scheduling tasks and modified a registry key, which provides persistence and can download the remote access trojan (RAT).

Using statistics provided by Bit.ly and Pastebin, Adamitis estimated that 2,000 systems interacted with the botnet sites every week. Although that doesn't mean that 2,000 system were infected each week, the number suggests that the activity continues to make the botnet a threat.

"This is one of those attacks that should be threat modeled and you should worry about, because this type of approach is going to affect a large number of people," Adamitis says.

Many attributes of the attack are hallmarks of the Gorgon Group, a Pakistan-affiliated team of cybercriminals, according to Prevailion. The Gorgon Group does not just focus on financial fraud and cybercrime but also conducts attacks against government organizations and has been linked to attacks against Spain, Russia, the United Kingdom, and the United States. The group has used a variety of software tools in the past, including njRAT, QuasarRAT, and Remcos, according to MITRE's ATT&CK framework.

The Prevailion researchers recommend that companies protect their systems with updated security software, firewalls, and some form of attack detection. Both of the initial file-infection vectors — using a macro to install software and exploiting a 2-year-old vulnerability — would be caught by most forms of modern endpoint security.

In addition, properly updated endpoint security software would have stopped the RAT from running, according to the researchers' analysis.

Related Content

Check out The Edge, Dark Reading's new section for features, threat data, and in-depth perspectives. Today's top story: "The Inestimable Values of an Attacker's Mindset & Alex Trebek."

Veteran technology journalist of more than 20 years. Former research engineer. Written for more than two dozen publications, including CNET News.com, Dark Reading, MIT's Technology Review, Popular Science, and Wired News. Five awards for journalism, including Best Deadline ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Oldest First  |  Newest First  |  Threaded View
Data Privacy Protections for the Most Vulnerable -- Children
Dimitri Sirota, Founder & CEO of BigID,  10/17/2019
Sodinokibi Ransomware: Where Attackers' Money Goes
Kelly Sheridan, Staff Editor, Dark Reading,  10/15/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
7 Threats & Disruptive Forces Changing the Face of Cybersecurity
This Dark Reading Tech Digest gives an in-depth look at the biggest emerging threats and disruptive forces that are changing the face of cybersecurity today.
Flash Poll
2019 Online Malware and Threats
2019 Online Malware and Threats
As cyberattacks become more frequent and more sophisticated, enterprise security teams are under unprecedented pressure to respond. Is your organization ready?
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-18214
PUBLISHED: 2019-10-19
The Video_Converter app 0.1.0 for Nextcloud allows denial of service (CPU and memory consumption) via multiple concurrent conversions because many FFmpeg processes may be running at once. (The workload is not queued for serial execution.)
CVE-2019-18202
PUBLISHED: 2019-10-19
Information Disclosure is possible on WAGO Series PFC100 and PFC200 devices before FW12 due to improper access control. A remote attacker can check for the existence of paths and file names via crafted HTTP requests.
CVE-2019-18209
PUBLISHED: 2019-10-19
templates/pad.html in Etherpad-Lite 1.7.5 has XSS when the browser does not encode the path of the URL, as demonstrated by Internet Explorer.
CVE-2019-18198
PUBLISHED: 2019-10-18
In the Linux kernel before 5.3.4, a reference count usage error in the fib6_rule_suppress() function in the fib6 suppression feature of net/ipv6/fib6_rules.c, when handling the FIB_LOOKUP_NOREF flag, can be exploited by a local attacker to corrupt memory, aka CID-ca7a03c41753.
CVE-2019-18197
PUBLISHED: 2019-10-18
In xsltCopyText in transform.c in libxslt 1.1.33, a pointer variable isn't reset under certain circumstances. If the relevant memory area happened to be freed and reused in a certain way, a bounds check could fail and memory outside a buffer could be written to, or uninitialized data could be disclo...