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.

Partner Perspectives  Connecting marketers to our tech communities.
SPONSORED BY
5/2/2017
10:10 AM
Thomas Reed
Thomas Reed
Partner Perspectives
Connect Directly
Twitter
RSS
50%
50%

OSX.Bella: Mac Malware Strikes Again

This variant of the OSX.Dok dropper behaves altogether differently, and installs a completely different payload.

On Friday, a sophisticated Mac Trojan was discovered called OSX.Dok, which installs malware designed to intercept all HTTP and HTTPS traffic. This morning, Adam Thomas, a Malwarebytes researcher, found a variant of the OSX.Dok dropper that behaves altogether differently and installs a completely different payload.

Distribution Method
This variant has the same form as the dropper for OSX.Dok – a zipped app named Dokument.app, masquerading as a document. It is signed with the same (now revoked) certificate as the previous OSX.Dok dropper and it was first uploaded to VirusTotal around the same time.

OSX.Dok.B SHA-256:
54ee71f6ad1f91a6f162bd5712d1a2e3d3111c352a0f52db630dcb4638101938

As with the previous variant, this one also copies itself to /Users/Shared/AppStore.app, and displays the same alert claiming that the app is damaged. However, this variant never displays the fake “OS X Updates Available” window, covering the entire screen. After a minute or so, it simply closes and deletes itself.

Instead of installing OSX.Dok, this dropper installs an open-source backdoor named Bella, created by someone who identifies himself on GitHub only as “Noah.”

Behavior Analysis
Noah has been creating Python scripts to attack various macOS data, such as stealing iCloud authorization tokens, or password and credit card information from Chrome. In February of this year, he released Bella, which combines functionality from previous scripts with new functionality:

  • Exfiltration of iMessage and SMS chat transcripts
  • Location of devices via Find My iPhone and Find My Friends
  • Phishing of passwords
  • Exfiltration of the keychain
  • Capture of data from the microphone and webcam
  • Creation and exfiltration of screenshots
  • Remote shell and screen sharing

Bella even includes the capability to escalate to root privileges via vulnerabilities in the system (which only work on macOS 10.12.1 and earlier), or phishing to obtain an admin user password. Some of the above capabilities rely on gaining root privileges, while others do not.

Image Source: Malwarebytes
Image Source: Malwarebytes

Bella can be customized in some aspects. This copy uses the following command server:

host = '185.68.93.74' #Command and Control IP (listener will run on)
port = 4545 #What port Bella will operate over

This address is owned by a hosting company located in Moscow, Russia.

The malware has also been set to install the script, database, and launch agent files in the following locations:

~/Library/Containers/.bella/Bella
~/Library/Containers/.bella/bella.db
~/Library/LaunchAgents/com.apple.iTunes.plist

If root access can be achieved, it will instead be placed in the corresponding locations in the root library folder, rather than the user’s library folder.

Conclusion
Although this particular delivery app is dead at this point, Bella is open-source and surprisingly powerful for a Python script. It’s quite likely that it will be dropped by other malicious installers in the future.

Malwarebytes for Mac detects this malware as OSX.Bella. If you’ve been infected with this malware, after removing it, be sure to change all your passwords as well. Business users should be aware that this malware could exfiltrate a large amount of company data, including passwords, code signing certificates, hardware locations and much more. If you’ve been infected, contact your IT department.

Related Content:

OSX.Dok: New & Sophisticated Mac Malware Strikes

Thomas Reed is a self-trained developer and Apple security expert, and is director of Mac offerings at Malwarebytes. View Full Bio
Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Dewes
50%
50%
Dewes,
User Rank: Apprentice
4/21/2018 | 3:49:14 PM
Malware Attacks.
Malware is like a terrorist for our computers. This is the serious news that it attacks mac again. That is so harmful to apple production. Mac community creates special security for their systems. thank you for all this information. This is a very good news and also bad for mac users.

<a href="https://lenovosupport.net/">Lenovo Support</a>
Aviation Faces Increasing Cybersecurity Scrutiny
Kelly Jackson Higgins, Executive Editor at Dark Reading,  8/22/2019
Microsoft Tops Phishers' Favorite Brands as Facebook Spikes
Kelly Sheridan, Staff Editor, Dark Reading,  8/22/2019
MoviePass Leaves Credit Card Numbers, Personal Data Exposed Online
Kelly Sheridan, Staff Editor, Dark Reading,  8/21/2019
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
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2016-6154
PUBLISHED: 2019-08-23
The authentication applet in Watchguard Fireware 11.11 Operating System has reflected XSS (this can also cause an open redirect).
CVE-2019-5594
PUBLISHED: 2019-08-23
An Improper Neutralization of Input During Web Page Generation (&quot;Cross-site Scripting&quot;) in Fortinet FortiNAC 8.3.0 to 8.3.6 and 8.5.0 admin webUI may allow an unauthenticated attacker to perform a reflected XSS attack via the search field in the webUI.
CVE-2019-6695
PUBLISHED: 2019-08-23
Lack of root file system integrity checking in Fortinet FortiManager VM application images of all versions below 6.2.1 may allow an attacker to implant third-party programs by recreating the image through specific methods.
CVE-2019-12400
PUBLISHED: 2019-08-23
In version 2.0.3 Apache Santuario XML Security for Java, a caching mechanism was introduced to speed up creating new XML documents using a static pool of DocumentBuilders. However, if some untrusted code can register a malicious implementation with the thread context class loader first, then this im...
CVE-2019-15092
PUBLISHED: 2019-08-23
The webtoffee &quot;WordPress Users &amp; WooCommerce Customers Import Export&quot; plugin 1.3.0 for WordPress allows CSV injection in the user_url, display_name, first_name, and last_name columns in an exported CSV file created by the WF_CustomerImpExpCsv_Exporter class.