Threats Tagged 'fileless execution'

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.