Target 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 new Windows implant called CLOSEDQUORUM, which operates without human operators by using four commercial large language models (LLMs) to autonomously decide on actions after deployment. The implant is a 16.4-megabyte executable that conducts reconnaissance on the target system and sends structured prompts to the LLMs, which respond with one of four actions: steal, inject, persist, or move. When the "steal" action is chosen, it simultaneously attacks three credential stores, extracting Windows credentials, browser passwords, and cryptocurrency wallet data. The "inject" action uses either Early Bird APC injection or process hollowing based on model recommendations. For persistence, it employs three overlapping mechanisms, including a Registry Run key, a scheduled task, and a WMI event subscription. To evade detection, CLOSEDQUORUM suppresses ETW telemetry and introduces delays before executing actions. It circumvents traditional command-and-control structures by calling legitimate API endpoints, making blocking these domains impractical. Talos introduced the CAIRN toolkit for detecting AI-integrated malware, which operates on metadata and employs rule-based detection. Unlike previous AI-assisted malware, CLOSEDQUORUM automates decision-making processes entirely, highlighting a significant evolution in malware capabilities. Security teams are advised to focus on behavioral detection strategies and utilize the YARA rule and CAIRN toolkit for identifying this threat.

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.

AppWizard

September 22, 2026

Google removes the age barrier for Gemini study notebooks

Google is expanding access to its study notebooks within the Gemini app, designed to assist learners by creating personalized study plans based on their notes and course materials. Users with school or work-issued Google accounts can create subject-specific notebooks, take progress check quizzes, and access custom lessons. The dynamic dashboard categorizes learning objectives into "Strengths" and "Focus areas" to help identify knowledge gaps. The rollout of this feature may take up to 15 days for all users, with immediate access not available for users in the European Economic Area (EEA), although support for EEA users will be introduced soon. Users must have these features enabled by their administrators to utilize the app fully.

Tech Optimizer

September 22, 2026

This fake LastPass Authenticator app will just shut off your antivirus and leave you open to attack

LastPass has identified a sophisticated scheme targeting users of its Authenticator app, involving SEO poisoning and deceptive GitHub pages that distribute malicious ZIP files disguised as legitimate software. Users searching for "LastPass Authenticator download" may encounter these counterfeit pages, which redirect them to a malicious server delivering a ZIP file containing vsdbg.exe and vsdbg.dll. The executable is a legitimate Microsoft debugging tool exploited to execute the malicious DLL through DLL sideloading, allowing the malware to run undetected. Named Rapuncel by security researchers from Delphos, this malware is undetectable by antivirus engines and targets a hardcoded list of 145 antivirus and endpoint security products, disabling them upon detection. Rapuncel harvests sensitive information, including saved passwords from over 25 web browsers, cryptocurrency wallet files from more than 30 applications, and session tokens from platforms like Discord and Steam. It also captures screenshots and compiles a profile of the infected system, uploading the stolen data to an attacker-controlled server. The malware includes a kernel driver that intercepts web traffic, allowing for advertisement injection and search result manipulation. This campaign has been active for several months, with LastPass vaults remaining unaffected. Users are advised to download applications only from trusted sources. Rapuncel establishes persistence on infected machines by installing itself as a Windows service that starts with the system and terminates activated security products. Removing the kernel driver requires booting into Safe Mode or using external recovery tools, as standard Windows utilities cannot eliminate software operating at that level.

Winsage

September 21, 2026

Windows 11 will soon reduce glare on your screen without ruining your photos or videos

Windows 11 is set to enhance its accessibility features, particularly with the Magnifier tool, introducing a new contrast theme that reduces glare without altering the colors of photos, videos, and charts. Users can activate this feature via the Magnifier toolbar and customize their preferences in the Accessibility settings. The Cloud rebuild feature will allow users to restore their PC to a clean state with options to sanitize drives during the process. IT administrators can also initiate a Cloud rebuild remotely. Live Captions will receive an update to include a setting that excludes audio from screen readers. Issues with Hyper-V related to sharing host folders with Linux VMs have been resolved. Additionally, a problem with File History backups failing has been fixed. Many of these updates have already been released to Insiders in the Beta Channel, and changes regarding Cloud rebuild are active in the Experimental Channel.

BetaBeacon

September 20, 2026

MuMu Player vs GameLoop vs KOPLAYER: Android 15 Gap

Android emulators for PC have become a crowded market with close to a dozen actively maintained clients. Tencent and NetEase have first-party products like GameLoop and MuMu Player to control the PC on-ramp to their mobile catalogs. Independent players like BlueStacks and LDPlayer focus on platform-agnostic performance and feature breadth. KOPLAYER appears to be abandoned in 2026 with no updates, functioning website, or active development. MuMu Player supports Android 15, offering newer features for mobile games. GameLoop is focused on Tencent's mobile titles with updated documentation. MuMu Player and GameLoop are free, while KOPLAYER is also historically free. MuMu Player and GameLoop have ongoing updates and security, while KOPLAYER's lack of updates poses a security risk.

AppWizard

September 19, 2026

The Ultimate APK Safety Checklist Every Android User Needs

Downloading an APK file allows Android users to access various applications, including those not available in official app stores. Users should consider the source, developer credibility, and requested permissions before installation. APK files are the format used by Android for app installation, and users may download them for reasons such as regional restrictions, needing older versions, or testing beta releases. APK files are not inherently unsafe; the risks arise from unknown sources, which may contain malware, tracking software, or other harmful elements. To ensure safety, users should verify the origin of the file, the developer's identity, and the permissions requested by the app. They should also scan APK files with security tools and be cautious of warning signs like unrealistic promises or missing developer information. A checklist before installation includes researching the app name, confirming the developer, reviewing permissions, checking security information, and monitoring the app after installation. Safe practices involve downloading from official sources, avoiding unknown websites, and keeping Android security updates current. Trusted information sources can help users make better decisions regarding APK files.

AppWizard

September 18, 2026

RatHat Android Malware Abuses ADB to Retain Shell Access After Uninstall

Cybersecurity experts have identified a new Android malware named RatHat, believed to be operated by Chinese threat actors. RatHat is distributed primarily through smishing and malvertising campaigns, leading users to deceptive download portals. It employs an automated multi-stage infection process and exploits Accessibility features along with a local ADB self-pairing mechanism to escape the Android application sandbox. The malware uses various anti-analysis techniques, including container tampering, manifest bombs, DEX bytecode poisoning, and dual string-encryption. RatHat's architecture consists of a malicious Android application, a Go agent, and an FRP reverse-proxy client, which together enable it to gain critical system permissions and perform various malicious activities such as credential capturing, screen recording, and SMS interception. Even if uninstalled, the malware retains shell access to the device, allowing attackers to reinstall it. RatHat can serialize the device's Accessibility tree to XML and communicate with a Generative AI assistant for tasks like screen coordinate determination and text extraction. The Go Agent, masquerading as a native library, exploits shell access to execute commands and establish a persistent connection to a command-and-control server via the FRP client. The C2 server can issue extensive commands to collect sensitive information, including SMS messages, credentials, files, and keystrokes, and RatHat also features a hardware-level keylogger.

AppWizard

September 17, 2026

New Chinese-Made ‘RatHat’ Android Malware Leverages AI to Steal Financial Data

Security researchers at Zimperium have identified a new strain of Android malware called RatHat, which is linked to threat actors from China and is designed to steal sensitive credentials and banking information. RatHat infiltrates devices through phishing sites, malvertising, and SMS phishing (smishing), tricking users into downloading malicious Android package kits (APKs). The malware uses a dropper to activate its payload, which is hidden in encrypted assets, and employs techniques to bypass Android's security measures. RatHat consists of three main components: a malicious Android application, a Go agent (liblocal-service.so), and an FRP client (libmedia_codec.so). The app collects sensitive information such as banking credentials, notifications, 2FA codes, OTP keys, and screen inputs. It features a generative AI user interface-automation engine that communicates in Mandarin and can perform various tasks like determining screen coordinates and issuing navigation commands. The Go agent acts as a command-and-control executor, executing commands to bypass app-level security and manage system-level tasks. The FRP client maintains a secure reverse tunnel to the attacker's server, allowing ongoing remote access to the device. The architecture of RatHat demonstrates the inadequacy of traditional mobile security measures against such advanced threats.