Remote Access Trojan Archives

Winsage

May 10, 2026

Official JDownloader site served malware to Windows and Linux users between May 6 and May 7

Between May 6 and May 7, 2026, the official JDownloader website was compromised in a supply chain attack, leading to the distribution of malicious installers for Windows and Linux users. Attackers altered download links, redirecting users to harmful files, specifically targeting the Windows “Alternative Installer” and the Linux shell installer. A Reddit user reported the issue after Microsoft Defender flagged the installers as malicious, noting unusual developer names instead of the expected publisher, AppWork GmbH. JDownloader developers confirmed the breach and temporarily took down the website for investigation, revealing that an unpatched vulnerability in the content management system allowed the attackers to modify download pages. The genuine installer packages were not altered, and the malicious links were removed. The website was restored on May 8–9, 2026, with verified clean installer links. Indicators of compromise included specific hashes and compromised URLs related to the attack.

Tech Optimizer

May 4, 2026

Microsoft Defender wrongly flags DigiCert certs as Trojan:Win32/Cerdigent.A!dha

Microsoft Defender mistakenly flagged legitimate DigiCert root certificates as Trojan:Win32/Cerdigent.A!dha, leading to their removal from Windows systems globally. This issue arose after a Defender signature update on April 30th, with affected certificates including 0563B8630D62D75ABBC8AB1E4BDFB5A899B24D43 and DDFB16CD4931C973A2037D3FC83A4D7D775D05E4. The certificates were removed from the AuthRoot store under the Registry key HKLMSOFTWAREMicrosoftSystemCertificatesAuthRootCertificates. Microsoft has addressed the issue in Security Intelligence update version 1.449.430.0, which also restored the removed certificates. The false positives were linked to detections related to a recent DigiCert breach, where threat actors obtained valid code-signing certificates used for signing malware. DigiCert revoked 60 code-signing certificates, including those linked to the "Zhong Stealer" malware campaign. The malware utilized certificates issued to companies like Lenovo and Kingston, but the certificates flagged by Microsoft Defender are root certificates and do not correspond to the revoked code-signing certificates.

Tech Optimizer

April 22, 2026

New STX RAT Uses Hidden Remote Desktop and Infostealer Features to Evade Detection

A newly identified remote access trojan, STX RAT, emerged in 2026, integrating hidden remote desktop access with credential theft features. The name "STX" comes from the Start of Text magic byte x02, which it appends to communications with its command-and-control (C2) server. Initial sightings were reported in late February 2026, when it was delivered via a browser-downloaded VBScript file to a financial organization. By early March, Malwarebytes noted a campaign distributing STX RAT through compromised FileZilla installers. Researchers from eSentire’s Threat Response Unit analyzed the malware, which includes extensive anti-analysis measures and employs techniques like AMSI-ghosting. Once operational, STX RAT connects to a C2 server at 95.216.51.236, transmitting system information securely. It targets saved credentials from applications like FileZilla and includes a Hidden Virtual Network Computing (HVNC) module, allowing attackers to control a victim's machine without detection. Security teams are advised to block the C2 IP and implement detection rules to mitigate the threat.

AppWizard

April 14, 2026

Mirax RAT Targets Android Devices Through Meta Apps

Mirax is a remote access Trojan (RAT) targeting Android devices in Spanish-speaking countries, identified by Outpost24's KrakenLabs in early March. It propagates fraudulent advertisements on Meta-owned applications, allowing cybercriminals to gain initial access. Mirax can interact with compromised devices in real time, converting them into residential proxy nodes through ads on platforms like Facebook and Instagram. It uses SOCKS5 protocol and Yamux multiplexing to establish proxy channels and uncover victims' IP addresses. The malware captures keystrokes, steals sensitive data, executes commands, and monitors user activity. It employs overlay pages to steal credentials and orchestrates distribution through Meta ads and GitHub for malicious APK files. Users are tricked into enabling installations from "unknown sources," and the malware disguises itself behind video playback features. Additionally, a threat actor has been offering Mirax as a malware-as-a-service (MaaS) on illicit forums, with subscription prices starting at ,500 for three months. This service is described as highly controlled and exclusive, primarily targeting Russian-speaking actors in underground communities.

Winsage

April 7, 2026

“This was not opportunistic. It was precision.” — How North Korean hackers used Microsoft Teams and Slack to compromise Windows PCs with an elaborate ploy

On March 30, 2026, axios, a JavaScript HTTP client library, was temporarily compromised by suspected North Korean hackers who hijacked maintainer Jason Saayman's account. This allowed them to publish two malicious versions of axios on npm. The malicious versions were identified and removed within three hours by StepSecurity. A post-mortem blog on GitHub provided security measures for users of Windows, macOS, and Linux, highlighting risks from a Remote Access Trojan (RAT) introduced during the breach. The attack was attributed to a group known as UNC1069, which has been active since at least 2018. Two weeks prior to the breach, Saayman was targeted in a social engineering campaign where attackers posed as a legitimate company founder, leading him to install the RAT via a fake update during a Microsoft Teams meeting. Microsoft Teams was not compromised; it was used as a delivery method for the Trojan. Saayman noted the operation's sophistication.

AppWizard

March 11, 2026

New BeatBanker Android malware poses as Starlink app to hijack devices

A newly identified Android malware called BeatBanker disguises itself as a Starlink application on fake Google Play Store websites. It functions as a banking trojan and includes Monero mining capabilities, allowing it to steal credentials and manipulate cryptocurrency transactions. Researchers at Kaspersky traced BeatBanker to campaigns targeting users in Brazil. The latest version uses the BTMOB RAT for remote access, enabling keylogging, screen recording, camera access, GPS tracking, and credential capture. BeatBanker is distributed as an APK file that decrypts and loads hidden code into memory, conducting environment checks before activation. It presents a fake Play Store update screen to trick users into granting permissions for additional payloads. To avoid detection, it delays malicious operations and plays a nearly inaudible MP3 file to maintain persistent activity. The malware uses a modified version of the XMRig miner to mine Monero on Android devices, connecting to mining pools through encrypted TLS connections. It can start or stop mining based on device conditions and uses Firebase Cloud Messaging to relay device information to its command-and-control server. Currently, BeatBanker infections have only been observed in Brazil, but there are concerns about its potential spread. Users are advised to avoid side-loading APKs from untrusted sources and to review app permissions regularly.

Winsage

March 2, 2026

Fake Xeno and Roblox Utilities Used to Install Windows RAT, Microsoft Warns

Cybersecurity experts at Microsoft Threat Intelligence have identified a trend where attackers distribute counterfeit gaming tools that install a remote access trojan (RAT) on users' systems. These trojanized executables, such as Xeno.exe or RobloxPlayerBeta.exe, are shared through browsers and chat platforms. The initial executable acts as a downloader, installing a portable Java runtime environment and launching a harmful Java archive, jd-gui.jar. Attackers use built-in Windows tools to execute commands via PowerShell and exploit trusted system binaries, minimizing detection risk. The embedded PowerShell script connects to remote locations, downloads an executable as update.exe, and executes it. The malware erases evidence of the downloader and modifies Microsoft Defender settings to allow RAT components to function undetected. It establishes persistence through scheduled tasks and a startup script named world.vbs, enabling prolonged access to the compromised device. Microsoft Defender can detect the malware and its behaviors, and organizations are advised to monitor outbound traffic and block identified domains and IP addresses. Users are encouraged to scrutinize Microsoft Defender exclusions and scheduled tasks for irregularities and remain cautious about downloading tools from unofficial sources.

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.

Tech Optimizer

February 16, 2026

Phishing Lures Spread XWorm Remote Access Trojan

A cyber-espionage campaign is utilizing the XWorm Remote Access Trojan (RAT) to infiltrate systems via phishing emails and a Microsoft Office vulnerability (CVE-2018-0802). XWorm, first detected in 2022, allows attackers remote control over infected computers for surveillance and data theft. The campaign uses business-oriented phishing emails with malicious Excel attachments that exploit the vulnerability to execute a fileless attack. The malware connects to a command-and-control server, encrypting communications and transmitting system details. XWorm features a plugin architecture with over 50 modules for various malicious activities, including credential theft and DDoS attacks. Security experts highlight the ongoing risk of legacy software vulnerabilities and recommend patching outdated components.

Winsage

February 13, 2026

Microsoft: New Windows LNK spoofing issues aren’t vulnerabilities

Security researcher Wietze Beukema revealed vulnerabilities in Windows LK shortcut files at the Wild West Hackin' Fest, which could allow attackers to deploy harmful payloads. He identified four undocumented techniques that manipulate these shortcut files, obscuring malicious targets from users. The vulnerabilities exploit inconsistencies in how Windows Explorer handles conflicting target paths, allowing for deceptive file properties. One technique involves using forbidden Windows path characters to create misleading paths, while another manipulates LinkTargetIDList values. The most sophisticated method alters the EnvironmentVariableDataBlock structure to present a false target in the properties window while executing malicious commands in the background. Microsoft declined to classify the EnvironmentVariableDataBlock issue as a security vulnerability, stating that exploitation requires user interaction and does not breach security boundaries. They emphasized that Windows recognizes shortcut files as potentially dangerous and provides warnings when opening them. However, Beukema noted that users often ignore these warnings. The vulnerabilities share similarities with CVE-2025-9491, which has been exploited by various state-sponsored and cybercrime groups. Microsoft initially did not address CVE-2025-9491 but later modified LNK files to mitigate the vulnerability after it was widely exploited.