• 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

Severe Hikvision HikCentral product flaws: What You Need to Know

 | 

U.S. CISA adds TP-Link Archer C7(EU) and TL-WR841N flaws to its Known Exploited Vulnerabilities catalog

 | 

Google addressed two Android flaws actively exploited in targeted attacks

 | 

U.S. CISA adds WhatsApp, and TP-link flaws to its Known Exploited Vulnerabilities catalog

 | 

Android droppers evolved into versatile tools to spread malware

 | 

Jaguar Land Rover shuts down systems after cyberattack, no evidence of customer data theft

 | 

Cloudflare blocked a record 11.5 Tbps DDoS attack

 | 

Palo Alto Networks disclosed a data breach linked to Salesloft Drift incident

 | 

Von der Leyen’s plane hit by suspected Russian GPS Jamming in Bulgaria, landed Safely

 | 

Supply-chain attack hits Zscaler via Salesloft Drift, leaking customer info

 | 

Crooks exploit Meta malvertising to target Android users with Brokewell

 | 

North Korea’s APT37 deploys RokRAT in new phishing campaign against academics

 | 

Fraudster stole over $1.5 million from city of Baltimore

 | 

SECURITY AFFAIRS MALWARE NEWSLETTER ROUND 60

 | 

Security Affairs newsletter Round 539 by Pierluigi Paganini – INTERNATIONAL EDITION

 | 

Amazon blocks APT29 campaign targeting Microsoft device code authentication

 | 

Lab Dookhtegan hacking group disrupts communications on dozens of Iranian ships

 | 

New zero-click exploit allegedly used to hack WhatsApp users

 | 

US and Dutch Police dismantle VerifTools fake ID marketplace

 | 

Experts warn of actively exploited FreePBX zero-day

 | 
  • 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
  • APT
  • Breaking News
  • Hacking
  • Malware
  • Lazarus APT exploited zero-day in Windows driver to gain kernel privileges

Lazarus APT exploited zero-day in Windows driver to gain kernel privileges

Pierluigi Paganini February 29, 2024

North Korea-linked Lazarus APT exploited a zero-day flaw in the Windows AppLocker driver (appid.sys) to gain kernel-level access to target systems.

Avast researchers observed North Korea-linked Lazarus APT group using an admin-to-kernel exploit for a zero-day vulnerability in the appid.sys AppLocker driver. 

The zero-day, tracked as CVE-2024-21338 has been addressed by Microsoft in the February Patch Tuesday update.

The nation-state actors exploited the zero-day to gain kernel-level access and disable security software. In past attacks threat actors achieved the same goal by using much noisier BYOVD (Bring Your Own Vulnerable Driver) techniques to cross the admin-to-kernel boundary. 

Lazarus exploited the vulnerability CVE-2024-21338 to perform direct kernel object manipulation in an updated version of their FudModule rootkit.

“the holy grail of admin-to-kernel is going beyond BYOVD by exploiting a zero-day in a driver that’s known to be already installed on the target machine. To make the attack as universal as possible, the most obvious target here would be a built-in Windows driver that’s already a part of the operating system.” reads the analysis published by Avast.

“Discovering an exploitable vulnerability in such a driver is significantly more challenging than in the previous BYOVD scenarios for two reasons. First, the number of possible target drivers is vastly smaller, resulting in a much-reduced attack surface. Second, the code quality of built-in drivers is arguably higher than that of random third-party drivers, making vulnerabilities much more difficult to find.” 

The new version of the rootkit can suspend PPL (Protected Process Light) protected processes associated with Microsoft Defender, CrowdStrike Falcon, and HitmanPro. 

The flaw CVE-2024-21338 resides within the IOCTL (Input and Output Control) dispatcher of the driver appid.sys. This driver is a core component of the AppLocker application, which is used to control which apps and files users can run. 

Lazarus exploited the zero-day in the appid.sys driver by manipulating the Input and Output Control (IOCTL) dispatcher. This manipulation allows them to arbitrary code on the target system, bypassing security measures.

“The entire goal of the admin-to-kernel exploit was to corrupt the current thread’s PreviousMode. This allows for a powerful kernel read/write primitive, where the affected user-mode thread can read and write arbitrary kernel memory using the Nt(Read|Write)VirtualMemory syscalls. Armed with this primitive, the FudModule rootkit employs direct kernel object manipulation (DKOM) techniques to disrupt various kernel security mechanisms. It’s worth reiterating that FudModule is a data-only rootkit, meaning it executes entirely from user space and all the kernel tampering is performed through the read/write primitive.” reads the report.

With their valuable admin-to-kernel zero-day exposed, Lazarus’s ability to bypass security has been significantly hampered. They must now choose between finding a new critical exploit or reverting to their older, less potent BYOVD tactics

The researchers noticed that with their valuable admin-to-kernel zero-day exposed, Lazarus’s ability to bypass security has been significantly hampered. They must now choose between finding a new critical exploit or reverting to their older, less potent BYOVD tactics.

Researchers published Indicators of Compromise (IoCs) and YARA for the latest version of the FudModule rootkit.

Follow me on Twitter: @securityaffairs and Facebook and Mastodon

Pierluigi Paganini

(SecurityAffairs – ransomware, Lazarus) 


facebook linkedin twitter

Hacking hacking news information security news IT Information Security Lazarus Pierluigi Paganini rootkit Security Affairs Security News zero-Day

you might also like

Pierluigi Paganini September 04, 2025
Severe Hikvision HikCentral product flaws: What You Need to Know
Read more
Pierluigi Paganini September 04, 2025
U.S. CISA adds TP-Link Archer C7(EU) and TL-WR841N flaws to its Known Exploited Vulnerabilities catalog
Read more

leave a comment

newsletter

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

    recent articles

    Severe Hikvision HikCentral product flaws: What You Need to Know

    Hacking / September 04, 2025

    U.S. CISA adds TP-Link Archer C7(EU) and TL-WR841N flaws to its Known Exploited Vulnerabilities catalog

    Hacking / September 04, 2025

    Crooks turn HexStrike AI into a weapon for fresh vulnerabilities

    Cyber Crime / September 03, 2025

    Google addressed two Android flaws actively exploited in targeted attacks

    Security / September 03, 2025

    U.S. CISA adds WhatsApp, and TP-link flaws to its Known Exploited Vulnerabilities catalog

    Hacking / September 03, 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