backdoor Archives

Winsage

August 14, 2026

Mustang Panda Adds Signed Windows Rootkit to CoolClient Backdoor for Stealth

The threat actor known as HoneyMyte, also referred to as Mustang Panda, has been deploying an upgraded version of the CoolClient backdoor, which includes a signed Windows kernel-mode rootkit. This rootkit enhances the malware's ability to conceal malicious processes, files, registry objects, and command-and-control (C2) network information. Victims have been identified in Myanmar, Mongolia, Pakistan, and Russia, with confirmed targets including government entities. The CoolClient backdoor is deployed as a secondary access layer following an initial PlugX infection. The kernel component activates when CoolClient gains full access to the Service Control Manager (SCM) and the SeTcbPrivilege privilege. If these conditions are not met, the malware bypasses driver deployment and advances to the final-stage implant. Kaspersky has provided indicators of compromise (IoCs), including file hashes, paths, and C2 domains. In a campaign targeting Myanmar, HoneyMyte used PlugX as the initial implant to deploy CoolClient, which involved creating Microsoft Defender exclusions and renaming a legitimate executable for DLL sideloading. Persistence is achieved through a scheduled task that executes the binary with SYSTEM privileges at startup. Execution begins when a legitimate application loads a malicious DLL, which then manages persistence, registry modifications, UAC bypass, process injection, driver deployment, and C2 communications. When privileges are granted, the malware extracts a kernel driver, writes it to disk, and establishes a driver service. The driver is digitally signed with a certificate from Nanjing Ranyi Technology Co., Ltd. The driver receives configuration data from the CoolClient user-mode component and utilizes specific IOCTL requests to register trusted processes and protect filesystem and registry paths. The rootkit can limit access rights to protected processes, hide processes by unlinking them from the active process list, and deny access to protected files and directories. It also filters C2 IPv4 addresses from network information. The driver incorporates 33 IOCTL handlers, but only three were observed in use during standard execution. Kaspersky shared several file hashes related to the malware, including those for the kernel driver and malicious DLLs. This follows earlier disclosures regarding a newer CoolClient variant and a different HoneyMyte kernel-mode rootkit documented in December 2025.

Winsage

August 14, 2026

APT group HoneyMyte upgrades CoolClient: the backdoor gets a kernel-level Windows rootkit

CoolClient is a sophisticated backdoor family linked to the HoneyMyte APT group, actively used in cyber-espionage campaigns targeting organizations in Asia and Russia since its initial disclosure in 2022. It has capabilities such as keylogging, clipboard theft, credential harvesting, and system reconnaissance. Investigations in 2023 revealed enhancements, including clipboard theft and HTTP traffic interception. By late 2025 and into 2026, a variant was noted that could deploy a signed kernel-mode driver as a Windows service, improving its stealth and operational capabilities. In a recent campaign targeting Myanmar, the HoneyMyte group used PlugX to deploy CoolClient components. They configured Microsoft Defender to exclude a fake Windows Defender installation directory and a renamed executable, defender.exe, to avoid detection. Persistence was achieved through a scheduled task that executed defender.exe with SYSTEM privileges at startup, which sideloaded the malicious libngs.dll to initiate the CoolClient execution chain. The latest CoolClient variant has a multi-stage execution chain, including: - defender.exe / Sang.exe: Exploited legitimate application for DLL sideloading. - libsrapc.dll: Benign dependency for the Sangfor application. - libngs.dll: First-stage loader that decrypts and loads the next stage. - loadcert.ini: Second-stage DLL implementing core functionalities. - cert.ini: Final-stage implant for command and control communication. - time.ini: Configuration file for CoolClient. The execution begins with the legitimate Sangfor application loading libngs.dll, which uses obfuscation to conceal its operations. The second stage, loadcert.ini, is injected into synchost.exe and performs tasks including persistence and process injection. The kernel-mode driver deployment routine involves decrypting time.ini, verifying privileges, and creating a service to execute the driver, enhancing stealth. The deployed kernel-mode driver, msagent.sys, is digitally signed and helps hide processes, files, and registry objects, making detection more difficult. The latest variant continues to target organizations consistent with previous HoneyMyte activities, with confirmed victims in Myanmar, Mongolia, Pakistan, and Russia, including government entities. The deployment of CoolClient as a secondary backdoor after a PlugX infection indicates a strategic approach to maintain access to compromised systems. The malware is confirmed as a new variant of CoolClient associated with the HoneyMyte threat group, with the kernel-mode driver marking a significant advancement in its capabilities.

AppWizard

July 31, 2026

Cheap Android TV Boxes Pose as Phones and Turn Owners’ Broadband Into Proxies

Bitsight's investigation revealed that inexpensive Android TV boxes are being shipped with applications that can change their hardware identity, allowing them to impersonate popular smartphone brands like Samsung and Huawei. This operation, named Fuyao, is linked to Zhejiang Fengwo IoT Technology Co., Ltd., a Chinese company established in 2019. The H96MAXV11 model was frequently reported among the affected devices. In one day, the operation received 65,957 reports from about 38,000 unique MAC addresses, with many devices misidentified as phones due to spoofed identifiers. Fengwo has also promoted over 120,000 "AI digital humans," though details on this marketing term are vague. The command-and-control server for Fuyao sends phone profiles to devices, masking their actual hardware specifications. The operation uses machine vision technology and a YOLOv8s object-detection model to identify advertisements. Bitsight documented 40 fraud tasks, 21 unique campaigns, and 166 modules across four devices. The operation's payout structure involves 144 operator-owned domains, with an estimated gross return of .25 per device daily, potentially leading to annual revenues in the millions. Attribution to Fengwo is supported by shared TLS certificate data and public patent records, although the patents do not directly address advertising. There is uncertainty about how the fraudulent apps were installed and at what point in the supply chain they were introduced. Device owners are advised to verify Play Protect certification and disconnect suspicious devices.

AppWizard

July 23, 2026

ThreatsDay: Android Spyware, PLC Attacks, AI Image Prompt Injection + 12 More Stories

GitHub will reject command-line support bundle uploads from outdated versions of GitHub Enterprise Server lacking security patches starting August 18, 2026. The npm package @copilot-mcp/apex has been identified as a post-install dropper that installs a macOS infostealer, phishing for sensitive information and maintaining a connection to an attacker's server. A rogue extension on the Microsoft Visual Studio Code marketplace, "Markdown All Pro," impersonates a legitimate tool and opens a backdoor after installation. A phishing campaign targeting Portuguese users delivers the Lampion banking malware, which has been active since 2019. DoubleVerify reports a rise in "AfterCall" apps that exploit user permissions for ad fraud. The GhostCommit attack method hides malicious instructions within PNG images in pull requests. The U.S. government has updated its advisory on Iranian-affiliated cyber activity targeting operational technology devices. An Android app posing as a civil defense alert system has been found to contain malware for data harvesting. An Iranian threat actor is distributing MarkiRAT malware through fake applications. An analysis of 28 AI-coded applications revealed 434 vulnerabilities, prompting Cisco to introduce Antares to identify vulnerabilities in codebases. A Russian-speaking threat actor is dismantling guardrails on AI models to create offensive tools.

Tech Optimizer

July 10, 2026

Hackers Use Fake VLC Executable and Malicious libvlc.dll to Deploy ValleyRAT

Cybercriminals are exploiting the VLC media player to install ValleyRAT, a remote access trojan, by embedding malware in a seemingly harmless file linked in phishing emails. The attack starts with an email that prompts the victim to download a ZIP archive containing a fake VLC executable and a malicious DLL named libvlc.dll. This method uses DLL sideloading to execute the malware under the guise of a legitimate application. Once executed, the malware establishes persistence by creating a registry entry and connects to a remote server to retrieve the final payload. ValleyRAT employs evasion tactics to avoid detection, including assessing system characteristics before executing harmful actions and using a fileless approach to deliver the payload directly into memory. Researchers have identified indicators of compromise, including specific SHA1 hashes and URLs associated with the malicious campaign.

Tech Optimizer

July 10, 2026

GigaWiper: Anatomy of a destructive backdoor assembled from multiple malware

Microsoft Threat Intelligence has identified the GigaWiper malware, which has been detected in compromised environments since October 2025. This malware has destructive capabilities and comes in two forms: standalone wiper binaries and larger binaries with backdoor functionalities, both developed in Golang. The standalone wiper operates at the physical disk level, overwriting disk content and removing partition references. The backdoor variant includes the same wiper functionality and adds persistence through a registry key and scheduled tasks, along with command and control communication via RabbitMQ and Redis. GigaWiper can execute various commands, including wiping drives, triggering a Blue Screen of Death (BSOD), file encryption that mimics ransomware behavior, and managing system elements. The malware integrates components from multiple malware families, including wipers and ransomware mechanisms, and has been linked to a previous malware known as FlockWiper. To defend against GigaWiper, organizations are advised to implement security measures such as tamper protection, blocking access to known C2 infrastructure, and utilizing endpoint detection and response solutions. Microsoft Defender provides detections for GigaWiper and related malware, and threat intelligence reports are available for customers to stay informed about threats. Indicators of compromise include specific SHA-256 hashes and IP addresses associated with GigaWiper.

Winsage

July 10, 2026

Microsoft Warns of GigaWiper Backdoor Built to Destroy Windows PCs

Microsoft has unveiled a destructive Windows backdoor named GigaWiper, which allows operators remote control over compromised systems to execute irreversible damage. GigaWiper originated from cyberattacks in October 2025 and is a composite of code from at least three malware families. It maintains its presence through a scheduled task disguised as “OneDrive Update,” executing at startup and every minute. GigaWiper can obliterate partition information, overwrite physical drives, and restart systems. It also mimics ransomware by encrypting files with the .candy extension, using randomly generated keys that are not stored, making recovery impossible. The malware has connections to the Crucio ransomware and resembles FlockWiper, with rewritten code in Go. GigaWiper features 20 command codes for various functions, including executing PowerShell instructions, managing processes, capturing screenshots, and remote access similar to VNC. It can remain on a system for surveillance until its destructive functions are activated. Microsoft Defender includes detection capabilities for GigaWiper, and users are advised to enable tamper protection and monitor for suspicious activities.

Tech Optimizer

July 6, 2026

MacPaw Moonlock antivirus review

MacPaw launched Moonlock as a standalone antivirus application in October 2025, building on its existing malware removal module from CleanMyMac. Moonlock focuses on educating users about malware rather than overwhelming them with technical details, following a 'care, not scare' philosophy. Research indicated that 66% of Mac users faced cyber threats last year, with a 67% increase in macOS backdoor variants in 2025. Moonlock Lab has identified new malware variants and maintains a strict zero-logs policy for its VPN. The application requires macOS 13 or later and 515MB of disk space, operates efficiently without significant performance impact, and necessitates a MacPaw account for installation. Support includes a knowledge base and email inquiries, but lacks live chat or phone options. Moonlock competes with ClamXAV, which is cheaper but lacks some features, and Intego Mac Internet Security X9, which offers a network monitor. Moonlock is priced at .95 per year for a single device, nearly double ClamXAV’s price for three devices, but includes additional features like a VPN and network inspection. It also provides a 30-day money-back guarantee.

Tech Optimizer

July 3, 2026

Hackers Use Fake VLC Executable and Malicious libvlc.dll to Deploy ValleyRAT

Cybercriminals are using a sophisticated method to bypass security measures by embedding malware within the VLC media player. This campaign exploits VLC to install ValleyRAT, a remote access trojan, through phishing emails that contain links to download a seemingly harmless file. Once the file is opened, it activates a hidden backdoor that evades detection by antivirus solutions. The malware has been active since 2023, with a significant increase in activity noted through 2025 and into 2026, particularly targeting Chinese and Japanese-speaking users. The infection process begins when a victim clicks a link in a phishing email, leading to a ZIP archive containing a disguised executable and a malicious DLL (libvlc.dll). The executable mimics a legitimate VLC file, and when executed, it loads the DLL, allowing the malware to run under the guise of VLC. The malware establishes persistence by creating a registry entry and connects to a remote server to retrieve the final payload. ValleyRAT employs evasion tactics to avoid detection, such as performing checks on system behavior and using a fileless approach to inject its payload directly into memory, avoiding storage on disk. Researchers recommend training employees to recognize suspicious filenames and deploying endpoint detection tools to identify DLL sideloading behavior. For organizations affected by this campaign, isolating compromised systems and reviewing security logs are critical initial steps. Indicators of compromise include a malicious email domain, a ZIP archive containing a fake VLC executable, and a download URL for ValleyRAT.

Winsage

June 30, 2026

A critical Windows 11 and Windows 10 flaw turns Microsoft Defender into a hacker’s best friend

Chaotic Eclipse, also known as Nightmare-Eclipse, bypassed Windows 11's BitLocker security using a USB stick and claimed Microsoft left a backdoor in the system. Following this, Microsoft patched three zero-day exploits named YellowKey, GreenPlasma, and MiniPlasma. Nightmare-Eclipse then revealed another zero-day vulnerability called RoguePlanet, which affects Microsoft Defender on Windows 10 and 11, potentially allowing attackers full control over compromised systems. Microsoft is tracking this vulnerability as CVE-2026-50656 and is working on a security update. Nightmare-Eclipse provided a proof-of-concept exploit and described it as a race condition with variable success rates. Microsoft has promoted Windows Defender as adequate for most users but acknowledged that third-party tools can offer additional protection. The company initially threatened legal action against Nightmare-Eclipse but later decided not to pursue lawsuits against researchers sharing their findings.