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

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>
Why CISOs Need a Security Reality Check
Joel Fulton, Chief Information Security Officer for Splunk,  6/13/2018
Cisco Talos Summit: Network Defenders Not Serious Enough About Attacks
Curtis Franklin Jr., Senior Editor at Dark Reading,  6/13/2018
Four Faces of Fraud: Identity, 'Fake' Identity, Ransomware & Digital
David Shefter, Chief Technology Officer at Ziften Technologies,  6/14/2018
Register for Dark Reading Newsletters
Partner Perspectives
What's This?
Malwarebytes protects businesses against malicious threats that escape detection by traditional antivirus solutions. Malwarebytes Anti-Malware, the companys flagship product, has a highly advanced heuristic detection engine that has removed more than five billion malicious threats from computers worldwide. SMBs and enterprise businesses worldwide trust Malwarebytes to protect their data. Founded in 2008, the company is headquartered in California with offices in Europe, and a global team of researchers and experts. For more information, please visit us at www.malwarebytes.com/business.
Featured Writers
White Papers
Video
Cartoon
Current Issue
Flash Poll
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2018-8030
PUBLISHED: 2018-06-20
A Denial of Service vulnerability was found in Apache Qpid Broker-J versions 7.0.0-7.0.4 when AMQP protocols 0-8, 0-9 or 0-91 are used to publish messages with size greater than allowed maximum message size limit (100MB by default). The broker crashes due to the defect. AMQP protocols 0-10 and 1.0 a...
CVE-2018-1117
PUBLISHED: 2018-06-20
ovirt-ansible-roles before version 1.0.6 has a vulnerability due to a missing no_log directive, resulting in the 'Add oVirt Provider to ManageIQ/CloudForms' playbook inadvertently disclosing admin passwords in the provisioning log. In an environment where logs are shared with other parties, this cou...
CVE-2018-11701
PUBLISHED: 2018-06-20
FastStone Image Viewer 6.2 has a User Mode Write AV at 0x005cb509, triggered when the user opens a malformed JPEG file that is mishandled by FSViewer.exe. Attackers could exploit this issue for DoS (Access Violation) or possibly unspecified other impact.
CVE-2018-11702
PUBLISHED: 2018-06-20
FastStone Image Viewer 6.2 has a User Mode Write AV at 0x00578cb3, triggered when the user opens a malformed JPEG file that is mishandled by FSViewer.exe. Attackers could exploit this issue for DoS (Access Violation) or possibly unspecified other impact.
CVE-2018-11703
PUBLISHED: 2018-06-20
FastStone Image Viewer 6.2 has a User Mode Write AV at 0x00402d6a, triggered when the user opens a malformed JPEG file that is mishandled by FSViewer.exe. Attackers could exploit this issue for DoS (Access Violation) or possibly unspecified other impact.