• Home
  • Cyber Crime
  • Cyber warfare
  • APT
  • Data Breach
  • Deep Web
  • Digital ID
  • Hacking
  • Hacktivism
  • Intelligence
  • Internet of Things
  • Laws and regulations
  • Malware
  • Mobile
  • Reports
  • Security
  • Social Networks
  • Terrorism
  • ICS-SCADA
  • POLICIES
  • Contact me
MUST READ

Qantas data breach impacted 5.7 million individuals

 | 

DoNot APT is expanding scope targeting European foreign ministries

 | 

Nippon Steel Solutions suffered a data breach following a zero-day attack

 | 

Iranian group Pay2Key.I2P ramps Up ransomware attacks against Israel and US with incentives for affiliates

 | 

Hackers weaponize Shellter red teaming tool to spread infostealers

 | 

Microsoft Patch Tuesday security updates for July 2025 fixed a zero-day

 | 

Italian police arrested a Chinese national suspected of cyberespionage on a U.S. warrant

 | 

U.S. CISA adds MRLG, PHPMailer, Rails Ruby on Rails, and Synacor Zimbra Collaboration Suite flaws to its Known Exploited Vulnerabilities catalog

 | 

IT Worker arrested for selling access in $100M PIX cyber heist

 | 

New Batavia spyware targets Russian industrial enterprises

 | 

Taiwan flags security risks in popular Chinese apps after official probe

 | 

U.S. CISA adds Google Chromium V8 flaw to its Known Exploited Vulnerabilities catalog

 | 

Hunters International ransomware gang shuts down and offers free decryption keys to all victims

 | 

SECURITY AFFAIRS MALWARE NEWSLETTER ROUND 52

 | 

Security Affairs newsletter Round 531 by Pierluigi Paganini – INTERNATIONAL EDITION

 | 

North Korea-linked threat actors spread macOS NimDoor malware via fake Zoom updates

 | 

Critical Sudo bugs expose major Linux distros to local Root exploits

 | 

Google fined $314M for misusing idle Android users' data

 | 

A flaw in Catwatchful spyware exposed logins of +62,000 users

 | 

China-linked group Houken hit French organizations using zero-days

 | 
  • Home
  • Cyber Crime
  • Cyber warfare
  • APT
  • Data Breach
  • Deep Web
  • Digital ID
  • Hacking
  • Hacktivism
  • Intelligence
  • Internet of Things
  • Laws and regulations
  • Malware
  • Mobile
  • Reports
  • Security
  • Social Networks
  • Terrorism
  • ICS-SCADA
  • POLICIES
  • Contact me
  • Home
  • Breaking News
  • Cyber Crime
  • Hacking
  • Malware
  • Microsoft details techniques of Mac ransomware

Microsoft details techniques of Mac ransomware

Pierluigi Paganini January 06, 2023

Microsoft warns of different ransomware families (KeRanger, FileCoder, MacRansom, and EvilQuest) targeting Apple macOS systems.

Microsoft Security Threat Intelligence team warns of four different ransomware families (KeRanger, FileCoder, MacRansom, and EvilQuest) that impact Apple macOS systems.

The initial vector in attacks involving Mac ransomware typically relies on user-assisted methods, such as downloading and running fake or weaponized applications. The ransomware can also be delivered as a second-stage payload dropper or part of a supply chain attack. 

The experts state that malware creators abuse legitimate functionalities and implement various techniques to exploit vulnerabilities, evade defenses, or trick users into infecting their devices.

One of the most important capabilities of ransomware is the capability of targeting specific files to encrypt. Microsoft researchers observed various techniques used by ransomware families to enumerate files and directories on Mac.

FileCoder and MacRansom use the Linux find utility to search for selected files to encrypt. 

The FileCoder ransomware, for example, searches the “/Users” and “/Volumes” directories by invoking the find command twice, using different paths to enumerate and excluding the README file while searching the “/Users” path.

mac ransomware

The researchers reported that KeRanger and EvilQuest use a sequence of opendir(), readdir(), and closedir() library functions to get the list of files.

The KeRanger, MacRansom, and EvilQuest ransomware families utilize a combination of hardware- and software-based checks to avoid being executed in a virtual environment for analysis and debugging purposes.

Hardware-based checks include checking a device’s hardware model (MacRansom), checking the logical and physical processors of a device (MacRansom), checking the MAC OUI of the device (EvilQuest), and checking the device’s CPU count and memory size (EvilQuest).

Code-related checks include delayed execution (KeRanger), PT_DENY_ATTACH (PTRACE) for an anti-debugging trick that prevents debuggers from attaching to the current malware process (EvilQuest and MacRansom), P_TRACED flag to check whether malware is being debugged (EvilQuest), and time-based check (EvilQuest).

Persistence is maintained by creating launch agents or launch daemons or using kernel queues.

“The ransomware families we analyzed often share similar anti-analysis and persistence techniques. However, these same ransomware families differ in encryption logic. Some use AES-RSA encryptions, while others use system utilities, XOR routine, or custom encryption logic to encrypt files. These encryption methods range from in-place modification to creating a new file while deleting the original one.” reads the analysis published by Microsoft. “Common among the ransomware observed is adding a new extension or simply encrypting the file without adding any new one.”

While FileCoder uses the ZIP utility to encrypt files, KeRanger uses AES encryption in Cipher block chaining (CBC) mode to encrypt files. MacRansom employes a symmetric algorithm for encrypting files and decrypting its ransom note “._README_”. 

EvilQuest also uses a custom symmetric key encryption routine to encrypt victims’ files.

The researchers observed two EvilQuest variants using two mechanisms of keylogging (T1056.001), the API CGEventTapCreate and the IOHIDManagerCreate API.

EvilQuest uses a set APIs (NSCreateObjectFileImageFromMemory, NSLinkModule, NSLookupSymbolInModule, NSAddressOfSymbol) to implement in-memory execution-

“Ransomware continues to be one of the most significant threats affecting any platform. Our analysis of ransomware on Mac operating systems shows how its creators use various techniques to remain hidden from automated analysis systems or make manual inspection by analysts challenging.” Microsoft concludes. “Understanding ransomware routines and their effects on any device or platform is essential for individual users to take steps toward device and data protection.”

Follow me on Twitter: @securityaffairs and Facebook and Mastodon

[adrotate banner=”9″][adrotate banner=”12″]

Pierluigi Paganini

(SecurityAffairs – hacking, Mac ransomware)

[adrotate banner=”5″]

[adrotate banner=”13″]


facebook linkedin twitter

Apple Cybercrime EvilQuest FileCoder Hacking hacking news information security news IT Information Security KeRanger macOS macransom malware Pierluigi Paganini Security Affairs Security News

you might also like

Pierluigi Paganini July 10, 2025
Qantas data breach impacted 5.7 million individuals
Read more
Pierluigi Paganini July 10, 2025
DoNot APT is expanding scope targeting European foreign ministries
Read more

leave a comment

newsletter

Subscribe to my email list and stay
up-to-date!

    recent articles

    Qantas data breach impacted 5.7 million individuals

    Data Breach / July 10, 2025

    DoNot APT is expanding scope targeting European foreign ministries

    APT / July 10, 2025

    Nippon Steel Solutions suffered a data breach following a zero-day attack

    Data Breach / July 09, 2025

    Iranian group Pay2Key.I2P ramps Up ransomware attacks against Israel and US with incentives for affiliates

    Malware / July 09, 2025

    Hackers weaponize Shellter red teaming tool to spread infostealers

    Malware / July 09, 2025

    To contact me write an email to:

    Pierluigi Paganini :
    pierluigi.paganini@securityaffairs.co

    LEARN MORE

    QUICK LINKS

    • Home
    • Cyber Crime
    • Cyber warfare
    • APT
    • Data Breach
    • Deep Web
    • Digital ID
    • Hacking
    • Hacktivism
    • Intelligence
    • Internet of Things
    • Laws and regulations
    • Malware
    • Mobile
    • Reports
    • Security
    • Social Networks
    • Terrorism
    • ICS-SCADA
    • POLICIES
    • Contact me

    Copyright@securityaffairs 2024

    We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept All”, you consent to the use of ALL the cookies. However, you may visit "Cookie Settings" to provide a controlled consent.
    Cookie SettingsAccept All
    Manage consent

    Privacy Overview

    This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities...
    Necessary
    Always Enabled
    Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
    Non-necessary
    Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.
    SAVE & ACCEPT