This investigation reveals a tech-support scam leveraging legitimate remote-access software UltraViewer and bulk-mailing software UltraMailer. A QuickBooks phishing campaign uses over 350 lookalike domains and tracking domains to direct victims to scammers attempting credential theft. UltraMailer is abused as a spamming tool with no abuse-reporting mechanism and is promoted on criminal forums. Trojanized installers containing authentic UltraViewer and UltraMailer copies, including one with njRAT malware, were found. The campaign briefly switched to another mailing service but resumed using UltraMailer after suspension. There is no evidence of developer involvement, but the findings highlight widespread criminal misuse of legitimate applications.
SiriusQT is a Windows Remote Access Trojan (RAT) distributed as Malware-as-a-Service since April 2026. It offers advanced capabilities including hidden VNC, credential theft, cryptocurrency wallet collection, clipboard monitoring, keylogging, process injection, and persistence. The malware uses custom encrypted command-and-control communication and has both native C++ and .NET loader variants. It is distributed primarily by a reseller named GhostKernel and targets victims in several European countries including the UK, Germany, France, Spain, Italy, and the Netherlands.
KGB RAT is a Windows Remote Access Trojan actively marketed on underground forums since late 2025. It is sold as Malware-as-a-Service with prices ranging from $150 to $800. The malware includes features such as credential theft, keylogging, hidden desktop takeover, ransomware, and psychological harassment tools like screamers and forced blue screens. It uses a daily updated fully undetectable (FUD) crypter to evade detection by Windows Defender and communicates with its command and control (C2) servers without requiring port forwarding. Notifications are delivered via Telegram. The malware is based on the NjRAT framework and includes a CryptoClipper module that swaps cryptocurrency wallet addresses. Development reportedly began in early 2022.
Threat actors are exploiting anticipation for Grand Theft Auto VI by distributing malicious ISO files disguised as leaked game versions. These fake installers are spread through SEO poisoning, gaming forums, social media, and torrenting sites. The analyzed ISO contains multiple malicious components including several RAT variants (NJRAT and DCRAT), Mercurial Grabber infostealer, Chaos ransomware functioning as a wiper, and Yandex Browser. When executed, the fake installer displays Russian-language messages and deploys malware to %TEMP% folders. The package includes data exfiltration capabilities, credential theft, system control features, and destructive file encryption. Based on Russian language usage throughout the infection chain, the campaign appears to target Russian-speaking gamers. The malware components date back to 2023, suggesting repurposed tools for this opportunistic attack.
Sable Squirrel operates a massive criminal enterprise controlling over 10,000 domains, spending an estimated $7 million acquiring expired domains to inherit their reputation and traffic. The actor runs illegal Asian sports streaming services under brands like Xoilac, Cakhia, and 90phut, which funnel viewers to gambling platforms including VSBet and 8xbet. Analysis reveals over 31,000 malware samples connecting to Sable Squirrel infrastructure, including Quasar RAT, AsyncRAT, DCRat, and ransomware variants, with the same domains simultaneously hosting streaming content and serving as command-and-control servers. Despite Vietnamese law enforcement actions in early 2026, including arrests and asset seizures, the operation quickly recovered and expanded for the World Cup, demonstrating resilience through domain rotation and shared technical infrastructure spanning multiple Asian markets.
Between May and July 2026, researchers tracked the Latin America-focused threat actor Blind Eagle through multiple exposed staging servers, identifying significant toolkit evolution. Four key developments emerged: a third string-obfuscation scheme featuring JavaScript with custom AES S-box substitution, a RunPE loader using bare AutoIt3 interpreter staged via GitHub, a reusable 'Photo Studio' persistence mechanism shared across three distinct toolchains, and a materially upgraded AsyncRAT variant codenamed JC-46. This enhanced RAT incorporates Windows Notification Facility process injection, custom Base28 encoding, Hidden VNC banking-fraud capabilities with browser profile cloning, and a Chrome App-Bound Encryption v20 bypass. Despite operational security weaknesses including exposed directories and hardcoded credentials, the group demonstrates selective sophistication targeting banking operations across Spanish-speaking regions.
Group-IB analyzes Millenium RAT version 4.*, a remote access trojan that has undergone significant architectural changes from .NET to native C++, while continuing to leverage Telegram Bot API for command and control without requiring dedicated server infrastructure. The malware is distributed as Malware-as-a-Service by developer 'ShinyEnigma' for $50-90 USD. Active exploitation campaigns are conducted by threat actor cluster 'Y2K Operators' using social engineering tactics including fraudulent utilities, hacking toolkits, software cracks, gaming lures, and trojanized cybercrime tools. The trojan enables exfiltration of sensitive browser and system data, screenshot and audio capture, keylogging, and arbitrary executable downloads. Over 62,000 compromised endpoints across more than 160 countries have been identified, with 39,730 infections occurring in Q1 2026 alone, demonstrating accelerating infection rates.
Insikt Group has identified five distinct activity clusters linked to TAG-144 (Blind Eagle), targeting primarily Colombian government entities across local, municipal, and federal levels throughout 2024 and 2025. The clusters share similar tactics, techniques, and procedures (TTPs) such as using open-source and cracked remote access trojans (RATs), dynamic domain providers, and legitimate internet services (LIS) for staging. However, they differ in infrastructure, malware deployment, and operational methods. The group maintains an extensive operational infrastructure, employs various RATs, and uses multi-stage infection chains. TAG-144's primary focus appears to be credential theft and espionage, with evidence linking it to Red Akodon and compromised Colombian government email accounts used in spearphishing campaigns.
