Threats Tagged 'fileless execution'

This threat involves a Chinese-language executable disguised as a resume purportedly from a Beijing Institute of Technology graduate student. It delivers SNOWLIGHT and a fileless VShell RAT using a custom Go loader with sandbox evasion techniques. The malware targets mainland Chinese academics in electrical engineering, power systems, or AI research. It provides attackers with command execution, file access, screen capture, and lateral movement capabilities. The infection chain includes downloading a legitimate DOCX decoy and XOR-decoding a payload before launching the RAT. Attribution is unreliable due to the use of widely available cracked VShell components. No patch or fix is indicated.

A sophisticated phishing campaign targeting Indian businesses and taxpayers leverages GST-related themes to distribute Remcos RAT through a multi-stage .NET framework. Threat actors impersonate Government of India GST communications using fraudulent refund notifications with convincing ARN references. The attack chain begins with a malicious RAR archive containing a .NET executable that employs bitmap-based payload concealment techniques. Through successive stages including Windows Health Optimizer Plus.dll and perfgurd.dll, the malware deploys Remcos RAT entirely in memory, establishing persistence via PowerShell scripts and registry modifications. Command-and-control infrastructure utilizes dynamic DNS services with randomized subdomains under aofmokighoig.hath.network. The deployed Remcos RAT enables remote command execution, keylogging, credential harvesting, file manipulation, and comprehensive system reconnaissance capabilities, representing a financially motivated cybercrime operation specifically t...

MediumMalwareBritish Indian Ocean TerritoryIndia#bitmap steganography#fileless execution#multi-stage loader

Since late March 2026, a large-scale phishing campaign has been deploying malware including Agent Tesla, Remcos, XWorm, and Best Private LOGGER through fileless techniques and low-detection Lua-based loaders. Attackers impersonate well-known companies using business cooperation lures to distribute malicious archives containing obfuscated JavaScript files. These scripts deploy either AutoIt or LuaJIT interpreters alongside disguised scripts masquerading as TrueType Font (.ttf) files. The Lua loaders employ sophisticated anti-analysis techniques including custom ROT ciphers, decoy memory allocation, and Donut shellcode generation for reflective in-memory payload execution. The campaign evolved from simpler implementations in October 2025 to highly complex versions by June 2026, incorporating API unhooking and advanced debugging countermeasures. Victims are ultimately infected with Remote Access Trojans and infostealers that enable full system control and extensive data exfiltration.

A sophisticated China-aligned cyber espionage campaign targeting India's tax infrastructure was identified between May and June 2026. The operation impersonates the Income Tax Department, Ministry of Finance, exploiting the AY2026-27 ITR filing season to target corporate entities, tax professionals, chartered accountants, and taxpayers. The attack employs spear-phishing emails with malicious attachments mimicking legitimate government utilities. The multi-stage infection chain deploys DcRAT through steganographic payload concealment, fileless .NET execution, AMSI bypass, and Windows service persistence. The threat actor demonstrates operational maturity through active payload rotation achieving 0/66 detection rates, encrypted TLS-based C2 communications, and infrastructure hosted across multiple ASNs linked to China. The campaign shows overlaps with the China-nexus threat actor Silver Fox, featuring screen capture capabilities, data exfiltration, and systematic intelligence collection from high-value India...

MediumMalwareBritish Indian Ocean TerritoryIndia#china-nexus#income tax impersonation#spear-phishing

A multi-stage phishing campaign emerged in early May 2026, impersonating LinkedIn and Indeed through typosquatted domains to deliver malicious payloads. The attack chain begins with fake CAPTCHA pages distributed via Google Ads, leveraging the legacy Finger protocol and native Windows utilities. Victims are tricked into executing commands that deploy portable Python runtimes (CPython or IronPython), which then execute in-memory shellcode. The campaign delivers CastleLoader, a Malware-as-a-Service framework using ChaCha20 and RC4 encryption for C2 communications, followed by a Python-based remote access trojan. The RAT provides interactive shell control, in-memory payload execution, and persistence mechanisms. The campaign represents an evolution of browser-based social engineering, combining Living-off-the-Land binaries with Python-based delivery to maintain a fileless footprint and evade detection through legitimate system utilities.

The ClickFix campaign is a malware operation that has evolved from simple disk-based infections to advanced, obfuscated attacks using fake CAPTCHA pages to trick victims into running malicious PowerShell commands. Early variants used cleartext commands to download batch scripts deploying DeerStealer InfoStealer. Later versions employ fileless execution with XOR encryption or Base64 compression, running entirely in memory. The most advanced stage uses server-side polymorphism to dynamically generate unique obfuscated payloads per victim, delivering Vidar InfoStealer. The campaign has been active since March 2026, with increased activity through May, leveraging approximately 4,500 live domains. It uses techniques to evade forensic detection by deleting traces after execution.

A sophisticated multi-stage intrusion campaign was identified leveraging a weaponized PowerShell payload disguised as a JPEG image file (sysupdate.jpeg) to deploy a trojanized ConnectWise ScreenConnect instance for covert remote access. The attack likely originates through social engineering techniques including phishing emails or malicious attachments. Upon execution, the malware establishes a staging environment, retrieves additional payloads from attacker-controlled infrastructure, and dynamically compiles a custom launcher using Microsoft's legitimate .NET compiler (csc.exe) to evade detection. The intrusion abuses ComputerDefaults.exe and a malicious ms-settings registry hijack to perform a fileless UAC bypass and obtain elevated privileges. Once elevated, the malware deploys a persistent service masquerading as OneDriveServers and launches a modified ScreenConnect framework capable of credential interception, remote command execution, surveillance operations, SYSTEM-level execution, encrypted command...

A sophisticated ClickFix campaign was detected in mid-March 2026, beginning with a malicious webpage impersonating Booking.com's visual identity with a fake CAPTCHA. The attack leverages social engineering to trick victims into executing a PowerShell command that downloads and runs a script directly in memory. The JavaScript code automatically copies malicious commands to the clipboard and intercepts copy events. Once executed, the PowerShell dropper performs system fingerprinting, downloads a ZIP payload from a remote server, deploys it to user directories, establishes persistence through registry keys and scheduled tasks, and executes the final payload. The campaign demonstrates well-structured code with fallback mechanisms and real-time telemetry via Telegram, suggesting the use of a ready-to-use attack kit.

A sophisticated malware campaign delivering PureLog Stealer has been identified, targeting healthcare, government, hospitality, and education sectors in multiple countries. The attack uses localized copyright violation lures to trick victims into executing a multi-stage infection chain. The malware employs encrypted payloads, remote key retrieval, and fileless execution techniques to evade detection. It utilizes a Python-based loader and dual .NET loaders to run PureLog Stealer entirely in memory. The campaign incorporates AMSI bypass, registry persistence, screenshot capture, and victim fingerprinting for stealth and intelligence gathering. Evidence confirms communication with PureLog-associated infrastructure.

MediumMalwareUnited StatesUnited KingdomGermany+7#copyright lure#fileless execution#targeted campaign

This analysis examines a sophisticated attack chain targeting Windows systems through social engineering. It uses fake CAPTCHA verification pages to trick users into executing malicious PowerShell commands. The multi-stage infection process ultimately deploys the StealC information stealer, a commodity malware designed to harvest sensitive data. The attack chain includes PowerShell scripts, position-independent shellcode, and a PE downloader, utilizing techniques like reflective PE loading, API hashing, and process injection to evade detection. StealC's capabilities include stealing browser credentials, cryptocurrency wallets, Steam accounts, Outlook credentials, and system information. The malware uses encrypted C2 communication and operates without persistence, making it particularly stealthy.

MediumMalwareGermanyFranceUnited Kingdom+4#process injection#credential theft#social engineering