• 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

SonicWall fixed critical flaw in SMA 100 devices exploited in Overstep malware attacks

 | 

DSPM & AI Are Booming: $17.87B and $4.8T Markets by 2033

 | 

Stealth backdoor found in WordPress mu-Plugins folder

 | 

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

 | 
  • 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
  • Internet of Things
  • Malware
  • Security
  • New Mirai botnet targets TBK DVRs by exploiting CVE-2024-3721

New Mirai botnet targets TBK DVRs by exploiting CVE-2024-3721

Pierluigi Paganini June 09, 2025

A new variant of the Mirai botnet exploits CVE-2024-3721 to target DVR systems, using a new infection method.

Researchers from Russian cybersecurity firm Kaspersky discovered a new variant of the Mirai botnet that exploits a command injection vulnerability (CVE-2024-3721) in TBK DVR-4104 and DVR-4216 digital video recording devices.

During a review of the logs in their Linux honeypot system, the researchers noticed a suspect POST request linked to the potential exploitation of CVE-2024-3721.

“The request contains a malicious command that is a single-line shell script which downloads and executes an ARM32 binary on the compromised machine.” reads the analysis.

“Typically, bot infections involve shell scripts that initially survey the target machine to determine its architecture and select the corresponding binary. However, in this case, since the attack is specifically targeted at devices that only support ARM32 binaries, the reconnaissance stage is unnecessary.”

The Mirai botnet’s source code, made public nearly a decade ago, has since been widely reused and modified by cybercriminals to power large-scale botnets. The latest DVR-focused variant is also built on Mirai’s foundation but introduces new features like RC4 string encryption, anti-virtual machine checks, and anti-emulation tactics. While Mirai itself is well-known, this version brings fresh techniques worth examining.

This Mirai variant uses a simple RC4 algorithm to decrypt strings and uses XOR to obfuscate the key. Once decrypted, strings are stored in a global list for use during execution. The malware also includes anti-VM and anti-emulation checks by scanning running processes for signs of VMware or QEMU.

Mirai botnet

The malware also verifies its execution path against a list of allowed directories to avoid detection. If all checks pass, it proceeds to prepare the infected device to receive commands.

Most infections are in China, India, Egypt, Ukraine, Russia, Turkey, and Brazil. While the exact number of infected devices is unclear, Kaspersky found over 50,000 exposed DVRs, which are potential targets.

“Exploiting known security flaws in IoT devices and servers that haven’t been patched, along with the widespread use of malware targeting Linux-based systems, leads to a significant number of bots constantly searching the internet for devices to infect.” concludes the report. “Most of these bots don’t stay active after the device restarts because some device firmware doesn’t allow changes to the file system. To protect against infections like these, we recommend updating vulnerable devices as soon as security patches become available. Another thing to consider is a factory reset if your device is indeed vulnerable and exposed.”

Follow me on Twitter: @securityaffairs and Facebook and Mastodon

Pierluigi Paganini

(SecurityAffairs – hacking, botnet)


facebook linkedin twitter

botnet CVE-2024-3721 Cybercrime DVR Hacking hacking news information security news IoT malware Mirai Pierluigi Paganini Security Affairs Security News

you might also like

Pierluigi Paganini July 24, 2025
SonicWall fixed critical flaw in SMA 100 devices exploited in Overstep malware attacks
Read more
Pierluigi Paganini July 24, 2025
DSPM & AI Are Booming: $17.87B and $4.8T Markets by 2033
Read more

leave a comment

newsletter

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

    recent articles

    SonicWall fixed critical flaw in SMA 100 devices exploited in Overstep malware attacks

    Security / July 24, 2025

    DSPM & AI Are Booming: $17.87B and $4.8T Markets by 2033

    Security / July 24, 2025

    Stealth backdoor found in WordPress mu-Plugins folder

    Malware / July 24, 2025

    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

    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