Hidden Backdoor in CCleaner Security App Has Infected 2.3 Million People

Hidden Backdoor in CCleaner Security App Has Infected 2.3 Million People

Hackers have hidden a backdoor in a security application called CCleaner. So far it has 2 billion downloads and has infected 2.3 million people and counting.

Security researchers have discovered cyber criminals have installed a backdoor in a security application for PCs. Users of the Avast-owned CCleaners for Windows have been advised to update their software immediately.

Researchers at Cisco Talos discovered the threat on Sept. 13 after CCleaner 5.33 caused their systems to flag malicious activity. The company warned that the hack could be comparable to the NotPetya ransomware outbreak, which spread after a Ukrainian accounting app was infected.

The hacked application allows for download of further malware, such as ransomware or keyloggers, and there are fears that virtually billions could be impacted. The security app has 2 billion downloads and claims to be getting five million extra a week, making the threat even more severe.

The backdoor installed in the application would send encrypted information about the infected computer - the name of the computer, installed software and running processes - back to the hacker's server. The hackers also used what is known as a domain generation algorithm (DGA) whenever the criminal's server went down, the DGA could create new domains to receive and send stolen data. Researchers have noted that the use of a DGA shows that these hackers are very sophisticated.

Further investigation found that the CCleaner download server was hosting the backdoored app as far back as Sept. 11 and the affected version had been released on August 15. Which means for weeks the malware was spreading inside a supposedly-legitimate security software.

On Sept. 12, CCleaner released an untained version of the software, version 5.34.

Featured

  • The Future of Access Control: Cloud-Based Solutions for Safer Workplaces

    Access controls have revolutionized the way we protect our people, assets and operations. Gone are the days of cumbersome keychains and the security liabilities they introduced, but it’s a mistake to think that their evolution has reached its peak. Read Now

  • A Look at AI

    Large language models (LLMs) have taken the world by storm. Within months of OpenAI launching its AI chatbot, ChatGPT, it amassed more than 100 million users, making it the fastest-growing consumer application in history. Read Now

  • First, Do No Harm: Responsibly Applying Artificial Intelligence

    It was 2022 when early LLMs (Large Language Models) brought the term “AI” into mainstream public consciousness and since then, we’ve seen security corporations and integrators attempt to develop their solutions and sales pitches around the biggest tech boom of the 21st century. However, not all “artificial intelligence” is equally suitable for security applications, and it’s essential for end users to remain vigilant in understanding how their solutions are utilizing AI. Read Now

  • Improve Incident Response With Intelligent Cloud Video Surveillance

    Video surveillance is a vital part of business security, helping institutions protect against everyday threats for increased employee, customer, and student safety. However, many outdated surveillance solutions lack the ability to offer immediate insights into critical incidents. This slows down investigations and limits how effectively teams can respond to situations, creating greater risks for the organization. Read Now

  • Security Today Announces 2025 CyberSecured Award Winners

    Security Today is pleased to announce the 2025 CyberSecured Awards winners. Sixteen companies are being recognized this year for their network products and other cybersecurity initiatives that secure our world today. Read Now

New Products

  • ResponderLink

    ResponderLink

    Shooter Detection Systems (SDS), an Alarm.com company and a global leader in gunshot detection solutions, has introduced ResponderLink, a groundbreaking new 911 notification service for gunshot events. ResponderLink completes the circle from detection to 911 notification to first responder awareness, giving law enforcement enhanced situational intelligence they urgently need to save lives. Integrating SDS’s proven gunshot detection system with Noonlight’s SendPolice platform, ResponderLink is the first solution to automatically deliver real-time gunshot detection data to 911 call centers and first responders. When shots are detected, the 911 dispatching center, also known as the Public Safety Answering Point or PSAP, is contacted based on the gunfire location, enabling faster initiation of life-saving emergency protocols.

  • PE80 Series

    PE80 Series by SARGENT / ED4000/PED5000 Series by Corbin Russwin

    ASSA ABLOY, a global leader in access solutions, has announced the launch of two next generation exit devices from long-standing leaders in the premium exit device market: the PE80 Series by SARGENT and the PED4000/PED5000 Series by Corbin Russwin. These new exit devices boast industry-first features that are specifically designed to provide enhanced safety, security and convenience, setting new standards for exit solutions. The SARGENT PE80 and Corbin Russwin PED4000/PED5000 Series exit devices are engineered to meet the ever-evolving needs of modern buildings. Featuring the high strength, security and durability that ASSA ABLOY is known for, the new exit devices deliver several innovative, industry-first features in addition to elegant design finishes for every opening.

  • A8V MIND

    A8V MIND

    Hexagon’s Geosystems presents a portable version of its Accur8vision detection system. A rugged all-in-one solution, the A8V MIND (Mobile Intrusion Detection) is designed to provide flexible protection of critical outdoor infrastructure and objects. Hexagon’s Accur8vision is a volumetric detection system that employs LiDAR technology to safeguard entire areas. Whenever it detects movement in a specified zone, it automatically differentiates a threat from a nonthreat, and immediately notifies security staff if necessary. Person detection is carried out within a radius of 80 meters from this device. Connected remotely via a portable computer device, it enables remote surveillance and does not depend on security staff patrolling the area.