process injection Archives

Tech Optimizer

August 18, 2026

The temporary download folder unleashes 35% of infostealers on Windows

Executing files directly from the temporary download folder is the primary gateway for infostealers targeting Windows systems, accounting for approximately 35% of analyzed infections. The second most common entry point is C:WindowsMicrosoft.NETFramework, appearing in 32% of cases and associated with advanced tactics like process injection. The findings are based on a report by Kaspersky, which analyzed five million records from the dark web. Malicious files often disguise themselves as legitimate software, such as fake codecs or program activators. Kaspersky recommends monitoring exposed assets and not disabling antivirus software during installations.

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.

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 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 2, 2026

PHANTOMPULSE RAT Uses UAC Bypass to Hijack Windows Systems

PHANTOMPULSE is a remote access trojan (RAT) used as a final payload in multi-stage attacks targeting Windows environments. It employs advanced post-exploitation techniques, including process injection, User Account Control (UAC) bypass, and a decentralized blockchain-based command-and-control (C2) mechanism. The malware utilizes three process injection techniques: module stomping, manual DLL mapping, and debug-driven execution. It avoids detection by using direct system calls instead of standard Windows APIs and incorporates a hardware breakpoint mechanism to disable security protections like AMSI and ETW. PHANTOMPULSE retrieves its C2 server address from Ethereum-based transaction data but has a vulnerability that allows defenders to hijack communication. It achieves persistence through scheduled tasks and supports self-healing capabilities. Privilege escalation is done using the "schuac" UAC bypass technique. The malware conducts system reconnaissance focusing on cryptocurrency wallets and messaging apps but does not directly steal credentials. It shows signs of AI-assisted development and shares tactics with DPRK-aligned threat groups, particularly in targeting cryptocurrency platforms.

AppWizard

April 21, 2026

Xbox PC Project Might Have Solved How To Fix Hundreds Of ‘Broken’ Windows Games

The Xbox Collection Tracker project on GitHub addresses connectivity issues faced by Windows 8-era games in the Xbox PC app due to the transition from XBL2.0 to XBL3.0 token formats. Microsoft has deprecated the old XBL2.0-formatted XSTS tokens, causing many older titles like Microsoft Mahjong, Minesweeper, Hydro Thunder Hurricane, and others to encounter sign-in errors and lose access to features tied to Xbox Live identity. The project aims to create a compatibility layer that allows these games to connect to Xbox servers using the modern XBL3.0 format without needing extensive modifications. Developers are advocating for a server-side translation layer to restore the functionality of these classic games while acknowledging potential security concerns.

Tech Optimizer

February 24, 2026

Fake Huorong Site Delivers ValleyRAT Backdoor in Targeted Malware Campaign

A cyber operation is targeting users of Huorong Security antivirus software through a typosquatted domain, huoronga[.]com, which mimics the legitimate site huorong.cn. Users who mistakenly visit the counterfeit site may download a file named BR火绒445[.]zip, which contains a trojanized installer that leads to the installation of ValleyRAT, a remote access trojan. The malware employs various techniques to evade detection, including using an intermediary domain for downloads, creating Windows Defender exclusions, and establishing a scheduled task for persistence. The backdoor facilitates activities such as keylogging and credential access while disguising its operations within legitimate processes like rundll32.exe. Attribution points to the Silver Fox APT group, and there has been a significant increase in ValleyRAT samples documented in recent months. Security measures include ensuring software downloads are from the official site and monitoring for specific malicious activities.

Winsage

February 20, 2026

Facebook ads spread fake Windows 11 downloads that steal passwords and crypto wallets

Attackers are using social media advertising, specifically paid Facebook ads, to promote a malware campaign disguised as legitimate Microsoft promotions. They create near-exact replicas of the official Windows 11 download page to lure users into downloading malicious software. The deceptive domains used include ms-25h2-download[.]pro and ms-25h2-update[.]pro. The malware campaign employs geofencing to selectively target victims, redirecting security researchers to benign sites while delivering malware to unsuspecting users. The malicious file, named ms-update32.exe, is hosted on GitHub and mimics the size of a legitimate Windows installer. Once executed, it checks for monitoring tools and, if none are detected, installs an application named "Lunar" that collects sensitive data, including cryptocurrency wallet information. The malware maintains persistence by writing data to the Windows registry and employs various obfuscation techniques to evade detection. The attackers run parallel ad campaigns with different Facebook Pixel IDs to ensure continued operation even if one is suspended. Indicators of compromise include specific file hashes, domains, file system artifacts, and registry keys associated with the malware.

Winsage

January 7, 2026

Hackers Use Fake Windows BSOD To Spread Malware

Security researchers have identified a social engineering campaign that mimics the Windows Blue Screen of Death (BSOD) to deceive users into installing a remote access Trojan (RAT). The campaign, named PHALT#BLYX, begins with phishing emails that appear to be legitimate cancellation notices from travel websites, leading victims to a fake login page and an interactive CAPTCHA. This culminates in a full-screen imitation of the BSOD, prompting users to follow instructions that ultimately allow attackers to gain control of their computers. The attackers use a “ClickFix” process that involves executing commands through native Windows tools like PowerShell and MSBuild, making detection more challenging. The malware delivered is an obfuscated version of DCRat, which provides attackers with remote control capabilities, keylogging, and the ability to download additional malware. The campaign primarily targets hotels and hospitality businesses in Europe, exploiting the urgency of front-desk staff to respond to apparent technical issues. Indicators of a fake BSOD include the ability to interact with the screen, requests to execute commands via Windows tools, and the presence of CAPTCHA prompts. Organizations are advised to train employees, implement application control, enhance email and web defenses, and prepare for incident response to mitigate risks associated with such attacks.