• 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

U.S. CISA adds CrushFTP, Google Chromium, and SysAid flaws to its Known Exploited Vulnerabilities catalog

 | 

U.S. CISA urges FCEB agencies to fix two Microsoft SharePoint flaws immediately and added them to its Known Exploited Vulnerabilities catalog

 | 

Sophos fixed two critical Sophos Firewall vulnerabilities

 | 

French Authorities confirm XSS.is admin arrested in Ukraine

 | 

Microsoft linked attacks on SharePoint flaws to China-nexus actors

 | 

Cisco confirms active exploitation of ISE and ISE-PIC flaws

 | 

SharePoint under fire: new ToolShell attacks target enterprises

 | 

CrushFTP zero-day actively exploited at least since July 18

 | 

Hardcoded credentials found in HPE Aruba Instant On Wi-Fi devices

 | 

MuddyWater deploys new DCHSpy variants amid Iran-Israel conflict

 | 

U.S. CISA urges to immediately patch Microsoft SharePoint flaw adding it to its Known Exploited Vulnerabilities catalog

 | 

Microsoft issues emergency patches for SharePoint zero-days exploited in "ToolShell" attacks

 | 

SharePoint zero-day CVE-2025-53770 actively exploited in the wild

 | 

Singapore warns China-linked group UNC3886 targets its critical infrastructure

 | 

U.S. CISA adds Fortinet FortiWeb flaw to its Known Exploited Vulnerabilities catalog

 | 

SECURITY AFFAIRS MALWARE NEWSLETTER ROUND 54

 | 

Security Affairs newsletter Round 533 by Pierluigi Paganini – INTERNATIONAL EDITION

 | 

Radiology Associates of Richmond data breach impacts 1.4 million people

 | 

Fortinet FortiWeb flaw CVE-2025-25257 exploited hours after PoC release

 | 

Authorities released free decryptor for Phobos and 8base ransomware

 | 
  • 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
  • Malware
  • PUMAKIT, a sophisticated rootkit that uses advanced stealth mechanisms 

PUMAKIT, a sophisticated rootkit that uses advanced stealth mechanisms 

Pierluigi Paganini December 15, 2024

Researchers discovered PUMAKIT, a Linux rootkit capable of hiding files, escalating privileges, and evading system tools and detection.

Elastic Security Lab researchers discovered a new loadable kernel module (LKM) rootkit called PUMAKIT that supports advanced evasion mechanisms.

PUMAKIT features a multi-stage design including a dropper, memory-resident executables, and a rootkit. It leverages an LKM rootkit named “PUMA,” using ftrace hooks to modify core system functions.

The malware hooks 18 syscalls and several kernel functions using ftrace() to hide files, directories, and the rootkit itself, while evading debugging attempts.

Developers focused on stealthy deployment, the malware activates only under specific conditions, such as secure boot checks or kernel symbol availability, embedding ELF binaries within its dropper.

“PUMAKIT is a sophisticated piece of malware, initially uncovered during routine threat hunting on VirusTotal and named after developer-embedded strings found within its binary.” reads the report published by Elastic Security Lab. “Key functionalities of the kernel module include privilege escalation, hiding files and directories, concealing itself from system tools, anti-debugging measures, and establishing communication with command-and-control (C2) servers.”

PUMAKIT

The LKM rootkit uses the syscall table to manipulate system behavior and relies on kallsyms_lookup_name() for symbol resolution. Unlike rootkits that target kernel versions 5.7 and above, the rootkit component of PUMAKIT does not use kprobes, suggesting it is designed for older kernels.

“This choice is significant because, prior to kernel version 5.7, kallsyms_lookup_name() was exported and could be easily leveraged by modules, even those without proper licensing.” continues the report.

“In February 2020, kernel developers debated the unexporting of kallsyms_lookup_name() to prevent misuse by unauthorized or malicious modules. A common tactic involved adding a fake MODULE_LICENSE("GPL") declaration to circumvent licensing checks, allowing these modules to access non-exported kernel functions. The LKM rootkit demonstrates this behavior”

The rmdir_hook() function in PUMAKIT’s kernel module intercepts rmdir() syscalls to manipulate directory operations. The malware uses it for privilege escalation and to retrieve configuration details based on a structured input pattern. The hook processes commands and arguments embedded in the syscall, starting with “zarya,” followed by command and argument characters. This structured system enhances control and concealment.

Below is the list of commands processed by the hook:

CommandPurpose
zarya.c.0Retrieve the config
zarya.t.0Test the working
zarya.k.<pid>Hide a PID
zarya.v.0Get the running version

Elastic Security developed a YARA signature to detect PUMAKIT components, including the dropper (cron), rootkit loader (/memfd:wpn), LKM rootkit, and Kitsune shared object files.

“PUMAKIT is a complex and stealthy threat that uses advanced techniques like syscall hooking, memory-resident execution, and unique privilege escalation methods. Its multi-architectural design highlights the growing sophistication of malware targeting Linux systems,” concludes the report.

Follow me on Twitter: @securityaffairs and Facebook and Mastodon

Pierluigi Paganini

(SecurityAffairs – hacking, malware)


facebook linkedin twitter

Hacking hacking news information security news IT Information Security malware Pierluigi Paganini PUMAKIT rootkit Security Affairs Security News

you might also like

Pierluigi Paganini July 24, 2025
U.S. CISA adds CrushFTP, Google Chromium, and SysAid flaws to its Known Exploited Vulnerabilities catalog
Read more
Pierluigi Paganini July 23, 2025
U.S. CISA urges FCEB agencies to fix two Microsoft SharePoint flaws immediately and added them to its Known Exploited Vulnerabilities catalog
Read more

leave a comment

newsletter

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

    recent articles

    U.S. CISA adds CrushFTP, Google Chromium, and SysAid flaws to its Known Exploited Vulnerabilities catalog

    Hacking / July 24, 2025

    U.S. CISA urges FCEB agencies to fix two Microsoft SharePoint flaws immediately and added them to its Known Exploited Vulnerabilities catalog

    Hacking / July 23, 2025

    Sophos fixed two critical Sophos Firewall vulnerabilities

    Security / July 23, 2025

    French Authorities confirm XSS.is admin arrested in Ukraine

    Cyber Crime / July 23, 2025

    Microsoft linked attacks on SharePoint flaws to China-nexus actors

    APT / July 23, 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