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

checkLoop 1checkLoop 2checkLoop 3
11/19/2019
04:45 PM
Connect Directly
Twitter
LinkedIn
Google+
RSS
E-Mail
50%
50%

Attacker Mistake Botches Cyborg Ransomware Campaign

Cybercriminals attempted to install Cyborg ransomware on target machines by deceiving victims with a fraudulent Windows update.

Install Latest Microsoft Windows Update now!

Critical Microsoft Windows Update!

These are the two subject lines of fraudulent emails disguised to appear as Windows Update notifications while containing malicious attachments to infect targets with Cyborg ransomware. While the threat is not effective, experts warn its public builder can be used to create variants.

This campaign has been ongoing since at least Nov. 7 and likely as early as Nov. 3, which was when the malware's GitHub repository was set up, says Karl Sigler, threat intelligence manager at Trustwave SpiderLabs, which discovered the campaign. Cyborg ransomware was also new to the research team who found this attack, which was seen spamming targets around the world.

"We have not seen this specific ransomware before, although our sample matches three other samples that have been uploaded to VirusTotal earlier this year," Sigler says. This ransomware could be a variant of ransomware that appends the "777" extension to encrypted files, he adds. The name "Cyborg" is likely a nod to the first recorded ransomware from 1989: PC Cyborg.

The emails, which claim to come from Microsoft, contain a single sentence: "PLease install the latest critical update from Microsoft attached to this email." Yes, "PLease" starts with two capital letters – a grammatical error that could tip users off to a potentially malicious message.

Trustwave researchers say the fake update attachment has a ".jpg" file extension but is, in fact, an executable file sized around 28KB with a randomized filename. The file is a malicious .NET downloader to deliver Cyborg ransomware to the system from Github. Researchers say the GitHub account was briefly active during their investigation but has since been taken down.

If the attackers had properly named the executable, it would have encrypted a victim's files once it landed on a machine. However, they changed the extension from ".exe" to ".jpg," says Sigler. "We often see attackers use double extensions in order to trick users into opening a file," he explains. For example, they may use "file.jpg.exe." By eliminating the ".exe" extension, the file would never execute unless an administrator purposely launched it from the command line.

"This campaign may have been a 'test balloon' of some sort, but as launched it would affect no one," Sigler says. It's unclear why Cyborg's operators chose to do this, but it's good news for all the potential victims who would not be infected if they opened the malicious attachments.

Inside Cyborg
In a blog post published today detailing their findings, researchers explained how they looked for additional variants of Cyborg by searching VirusTotal for "syborg1finf.exe," the original filename of the ransomware they obtained. They obtained three samples of the ransomware.

"The file extension these Cyborg ransomware samples will append to the encrypted files varies as observed from the samples found on VT," researchers wrote. This indicated a builder for Cyborg existed somewhere. A Web search revealed a YouTube video about "Cyborg Builder Ransomware V1.0 [ Preview free version 2019 ]," with a link to the Cyborg builder in Github.

A description below the video emphasizes the tool is designed for penetration testing and that illegal use of the software may send violators to prison. While this specific campaign is ineffective, the builder software is still available on Github and could be reused by anyone.

"After customizing the malware to their own needs, new attackers can use any number of social engineering type attacks or known exploits to install the malware," Sigler says.

The ransomware may also be spammed using other themes and attached in different forms to evade email gateways. Attackers can tailor the threat to use a known ransomware file extension, which can mislead infected users from Cyborg's identity, researchers explain.

Related Content:

Check out The Edge, Dark Reading's new section for features, threat data, and in-depth perspectives. Today's top story: "How Medical Device Vendors Hold Healthcare Security for Ransom."

Kelly Sheridan is the Staff Editor at Dark Reading, where she focuses on cybersecurity news and analysis. She is a business technology journalist who previously reported for InformationWeek, where she covered Microsoft, and Insurance & Technology, where she covered financial ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Data Leak Week: Billions of Sensitive Files Exposed Online
Kelly Jackson Higgins, Executive Editor at Dark Reading,  12/10/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Write a Caption, Win a Starbucks Card! Click Here
Latest Comment: Our Endpoint Protection system is a little outdated... 
Current Issue
The Year in Security: 2019
This Tech Digest provides a wrap up and overview of the year's top cybersecurity news stories. It was a year of new twists on old threats, with fears of another WannaCry-type worm and of a possible botnet army of Wi-Fi routers. But 2019 also underscored the risk of firmware and trusted security tools harboring dangerous holes that cybercriminals and nation-state hackers could readily abuse. Read more.
Flash Poll
Rethinking Enterprise Data Defense
Rethinking Enterprise Data Defense
Frustrated with recurring intrusions and breaches, cybersecurity professionals are questioning some of the industrys conventional wisdom. Heres a look at what theyre thinking about.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-19777
PUBLISHED: 2019-12-13
stb_image.h (aka the stb image loader) 2.23, as used in libsixel and other products, has a heap-based buffer over-read in stbi__load_main.
CVE-2019-19778
PUBLISHED: 2019-12-13
An issue was discovered in libsixel 1.8.2. There is a heap-based buffer over-read in the function load_sixel at loader.c.
CVE-2019-16777
PUBLISHED: 2019-12-13
Versions of the npm CLI prior to 6.13.4 are vulnerable to an Arbitrary File Overwrite. It fails to prevent existing globally-installed binaries to be overwritten by other package installations. For example, if a package was installed globally and created a serve binary, any subsequent installs of pa...
CVE-2019-16775
PUBLISHED: 2019-12-13
Versions of the npm CLI prior to 6.13.3 are vulnerable to an Arbitrary File Write. It is possible for packages to create symlinks to files outside of thenode_modules folder through the bin field upon installation. A properly constructed entry in the package.json bin field would allow a package publi...
CVE-2019-16776
PUBLISHED: 2019-12-13
Versions of the npm CLI prior to 6.13.3 are vulnerable to an Arbitrary File Write. It fails to prevent access to folders outside of the intended node_modules folder through the bin field. A properly constructed entry in the package.json bin field would allow a package publisher to modify and/or gain...
checkLoop 4