threats Archives

Tech Optimizer

September 23, 2026

BigDiskBuster PoC Blocks Windows Defender Updates

A new tool named BigDiskBuster has been released on GitHub, which disrupts Microsoft Defender Antivirus by preventing it from installing updates. It does this by consuming available disk space during the update process, causing Defender to remain on its current version and unable to receive new platform or signature updates. BigDiskBuster operates as a local denial-of-service technique and requires prior access to the target machine to execute. The tool was created by researcher Abdelhamid Naceri, known as Nightmare Eclipse, who has previously worked on similar projects. As of now, there is no CVE identifier, patch, or advisory from Microsoft regarding this issue.

Winsage

September 23, 2026

Cisco Talos Discloses Autonomous Windows Malware: Four AI Models Direct Each Attack

Cisco Talos has disclosed a Windows implant called CLOSEDQUORUM, which automates cyberattack execution using four advanced commercial large language models: DeepSeek, Qwen, Mistral, and Google Gemini. The implant is a 16.4-megabyte executable that conducts reconnaissance on the system and formats the gathered data into prompts for the AI models. Each model votes on one of four actions: steal, inject, persist, or move, with the action receiving the most votes being executed. When stealing, CLOSEDQUORUM targets three credential stores, dumping LSASS memory and retrieving saved passwords from browsers and cryptocurrency wallets. The stolen data is encrypted and sent to the operator via Discord. For injection, it uses Early Bird APC injection or process hollowing based on model responses. The persist action creates three mechanisms for longevity, including a Registry Run key, a scheduled task, and a WMI event subscription. CLOSEDQUORUM evades detection by suppressing ETW telemetry and delaying activity to avoid sandbox analyses. It connects to legitimate API endpoints, making blocking ineffective without disrupting enterprise applications. Talos recommends behavioral combination detection strategies and the use of a YARA rule for detection. The CAIRN toolkit has been introduced to detect AI-integrated malware without executing binaries. Unlike previous AI-assisted malware, CLOSEDQUORUM removes human decision-making from the attack process.

Winsage

September 23, 2026

New Windows Defender zero-day blocks Microsoft antivirus updates

Security researcher Abdelhamid Naceri, known as Nightmare Eclipse, released a zero-day exploit called BigDiskBuster that targets Microsoft Defender, preventing antivirus updates and leaving systems vulnerable. BigDiskBuster operates across all supported Windows versions and must run in the background to block updates. Naceri has previously released a similar exploit called UnDefend and has a history of releasing multiple zero-day exploits since April 2026 amid a dispute with Microsoft. Two weeks before BigDiskBuster, he introduced another exploit named ShieldCrash, which grants SYSTEM access and circumvents a patched flaw. Naceri's recent exploits include tools like LegacyHive, BlueHammer, RedSun, YellowKey, GreenPlasma, and MiniPlasma, all targeting Microsoft Defender and other Windows components. Microsoft has warned of potential legal action against malicious activities but has not commented on BigDiskBuster.

AppWizard

September 23, 2026

RatHat Android Malware Uses AI to Target Banking Credentials in Real Time

A newly identified strain of Android malware, RatHat, utilizes generative AI to manipulate infected devices in real time. It is linked to threat actors believed to be operating out of China. RatHat serializes the device’s live Accessibility tree into XML format and communicates with a generative AI assistant to return screen coordinates, identify text, and issue navigation commands. The malware employs WebView-based HTML overlays to capture login credentials from banking and cryptocurrency applications and can infiltrate payment apps like WeChat and Alipay to extract PINs. It also features an SMS receiver and notification listener to intercept OTPs and 2FA codes. RatHat is disseminated through smishing, malvertising campaigns, and misleading third-party forums. It employs anti-analysis techniques such as container tampering, manifest bombing, DEX bytecode poisoning, string encryption, and anti-debugging. Once installed, it gains Accessibility access, activates Developer Options, and enables Wireless Debugging, allowing it to connect to the device's local ADB service and launch control agents with shell-level privileges. The malware captures raw touch coordinates to reconstruct PINs and unlock patterns, bypassing screenshot protections. It also includes persistence mechanisms that prevent uninstallation by presenting a fake Google Play failure overlay and automatically reinstalling itself if removed.

Tech Optimizer

September 22, 2026

Kaspersky: 5 Security Essentials Beyond Built-In Antivirus

India's internet usage has rapidly evolved, with the Unified Payments Interface (UPI) transforming smartphones into banking hubs and daily tasks being conducted online. Despite this digital shift, many users rely on pre-installed security software, which may not be sufficient against increasing cyber threats. In 2025, nearly one in four internet users in India faced web-based cyber threats, with over 47.5 million threats blocked, averaging about 130,000 daily. Kaspersky's Safe Money feature provides real-time verification of banking and shopping sites, while its anti-phishing capabilities respond to rapidly changing scams. Scammers are using multi-channel approaches, prompting Kaspersky's system to flag suspicious activity across platforms. Credential theft increased by 20% in 2025, with over 225,000 attacks thwarted, and Kaspersky offers identity monitoring to alert users of data leaks. Additionally, Kaspersky Premium provides 24/7 human support for suspicious activities, addressing the limitations of standard antivirus tools in a complex digital threat landscape.

Tech Optimizer

September 22, 2026

When “Good Enough” Isn’t Enough: 5 Security Essentials Kaspersky Covers That Built-In Antivirus Doesn’t

India's digital landscape has rapidly evolved, with the Unified Payments Interface (UPI) turning smartphones into banking hubs and shifting many routine tasks online. However, users often rely on basic pre-installed security software, underestimating online threats. In 2025, nearly one in four internet users in India faced web-based threats, with over 47.5 million incidents blocked. Kaspersky addresses five critical gaps in online security: 1. Real-Time Site Verification: Kaspersky’s Safe Money feature provides real-time verification of banking and shopping sites, which standard antivirus tools lack. 2. Live Anti-Phishing Protection: Kaspersky offers real-time anti-phishing capabilities with a continuously updated threat database, responding faster than traditional antivirus solutions. 3. Cross-Channel Threat Detection: Kaspersky flags suspicious activities across multiple channels, unlike single-channel antivirus tools. 4. Identity and Data-Leak Monitoring: Kaspersky alerts users when their information appears on the dark web, integrating this feature into its protection suite. 5. Round-the-Clock Human Support: Kaspersky Premium provides 24/7 human support for users facing suspicious transactions or alerts. Credential theft targeting Indian networks increased by 20% in 2025, with over 225,000 attacks thwarted. The sophistication of digital threats in India has outpaced basic defenses, necessitating advanced protection layers.

Winsage

September 22, 2026

Microsoft Defender is causing slow VLC startups. Here’s the fix

Recent investigations have shown that a specific update to Microsoft Defender has caused performance issues for VLC Media Player, particularly a slowdown in startup times. Jean-Baptiste Kempf, a VideoLAN developer, attributed this sluggishness to a bug in the Microsoft Defender update, which quarantined VLC's plug-in cache. The problematic Defender signature update is version 1.455.50.0, linked to Windows Update KB5121003 released on August 11th. Users can reset the plug-in cache to improve performance by either reinstalling VLC or using the built-in functionality to regenerate the cache with vlc-cache-gen.exe. Alternatively, users can reset preferences and cache files by searching for "VLC" and selecting the reset option. Microsoft has not yet provided a fix for these issues, and users may need to set an exclusion in Microsoft Defender for VLC Media Player to prevent unnecessary scans, enhancing its performance.

Winsage

September 21, 2026

Do This If You Want Another Year of Windows 10 Security Updates

Microsoft has extended its security update support for Windows 10 until October 12, 2027, through the Extended Security Updates (ESU) program. This extension allows users to maintain essential protection against threats despite the official end of support last year. The ESU program will continue for existing participants without further action required, while new users can enroll until the program concludes next year. To qualify, devices must be running Windows 10 version 22H2 and have the latest updates installed. Enrollment options include purchasing coverage or redeeming Microsoft Rewards points. The program focuses solely on security, providing critical monthly updates without new features.

Tech Optimizer

September 21, 2026

Do You Really Need Antivirus in 2026?

The landscape of computer security has changed significantly over the past two decades. In 2026, antivirus protection remains important, but the need for separate third-party programs has decreased for many users due to the built-in Microsoft Defender in Windows 11, which is activated by default and effectively blocks 100% of common malware samples according to independent testing by AV-TEST. Windows 11 also includes additional protective features like SmartScreen and a robust Firewall. While dedicated security suites from companies like Norton and Bitdefender offer advanced functionalities, many users may find adequate protection with the built-in tools. Research from AV-Comparatives indicates that performance varies among security programs, particularly against real-world attacks. Phishing attacks accounted for approximately 60% of initial access points in incidents examined by the ENISA Threat Landscape report from 2025, highlighting that user behavior is a significant vulnerability. Modern web browsers and operating systems have enhanced their security measures, with Google Chrome, Microsoft Edge, macOS, and Android incorporating features to protect users from harmful websites and downloads. For the average Windows 11 user who keeps their system updated and practices safe browsing, built-in protection is generally sufficient, though paid antivirus options can provide additional tools.

Tech Optimizer

September 21, 2026

Thousands of hacked sites trick you into installing malware

More than 5,400 websites across over 2,200 organizations have been compromised to propagate malware, primarily affecting small businesses like clinics and online retailers. The attack mechanism involves malicious code that triggers a deceptive CAPTCHA, instructing users to execute commands that can download malware. Attackers are using the BNB Smart Chain test network to store instructions, making it harder for investigators to shut down operations. A newer variant of the attack uses WebRTC technology to establish encrypted connections for delivering additional malicious code. To protect against these threats, users should avoid pasting commands from websites, be suspicious of unusual CAPTCHA instructions, use strong antivirus protection, keep systems updated, take action if commands are executed, and small business owners should regularly verify their website's integrity.