QuirkyLoader Malware Distributes Multiple Payloads via Email Spam Campaigns

Two spyware families, ToSpy and ProSpy, are targeting Android users in the UAE by masquerading as the ToTok app and Signal encryption plugins. These campaigns have been active since 2022 and 2024, respectively, and exploit the popularity and local trust of ToTok to infiltrate devices and exfiltrate sensitive data. ToTok, a messaging app developed by G42 and supported by the UAE government, was exposed as spyware in 2019 and removed from major app stores. Despite this, it continues to circulate outside official channels, providing cover for malicious actors. The spyware families request invasive permissions to steal device information, contacts, SMS messages, and various file types. Google Play Protect is designed to mitigate these threats, but users are still at risk if they download apps from untrusted sources. The spyware campaigns are distributed via fake websites and social engineering, establishing persistent access to compromised devices. The ProSpy campaign was discovered in June 2025 and has been ongoing since 2024, while the ToSpy campaign began on June 30, 2022, and is currently ongoing. The spyware families use deceptive websites masquerading as legitimate services to distribute malware. The spyware families exfiltrate device information, SMS messages, contact lists, files, and a list of installed applications. The spyware families use Android's AlarmManager to repeatedly restart the foreground service if it gets terminated. The spyware families automatically launch the necessary background services upon a device reboot.

A new variant of the XCSSET macOS malware has been detected, targeting Xcode developers with enhanced features. This variant includes improved browser targeting, clipboard hijacking, and persistence mechanisms. The malware spreads by infecting Xcode projects, stealing cryptocurrency, and browser data from infected devices. The malware uses run-only compiled AppleScripts for stealthy execution and employs sophisticated encryption and obfuscation techniques. It incorporates new modules for data exfiltration, persistence, and clipboard monitoring. The malware has been observed in limited attacks, with Microsoft sharing findings with Apple and GitHub to mitigate the threat. Developers are advised to keep macOS and apps up to date and inspect Xcode projects before building them.

The UNC5221 activity cluster, attributed to suspected Chinese hackers, has been using the BRICKSTORM malware in long-term espionage operations against U.S. organizations in the technology, legal, SaaS, and BPO sectors. The malware, a Go-based backdoor, has been active for over a year, with an average dwell time of 393 days. It has been used to steal data from various sectors, including SaaS providers and BPOs. The attackers exploit vulnerabilities in edge devices and use anti-forensics techniques to avoid detection. The malware serves multiple functions, including web server, file manipulation, dropper, SOCKS relay, and shell command execution. It targets appliances without EDR support, such as VMware vCenter/ESXi, and uses legitimate traffic to mask its C2 communications. The attackers aim to exfiltrate emails and maintain stealth through various tactics, including removing the malware post-operation to hinder forensic investigations. The attackers use a malicious Java Servlet Filter (BRICKSTEAL) on vCenter to capture credentials, and clone Windows Server VMs to extract secrets. The stolen credentials are used for lateral movement and persistence, including enabling SSH on ESXi and modifying startup scripts. The malware exfiltrates emails via Microsoft Entra ID Enterprise Apps, utilizing its SOCKS proxy to tunnel into internal systems and code repositories. UNC5221 focuses on developers, administrators, and individuals tied to China's economic and security interests. Mandiant has released a free scanner script to help defenders detect BRICKSTORM. The BRICKSTORM backdoor is under active development, with a variant featuring a delay timer for C2 communication. The attackers have exploited Ivanti Connect Secure zero-day vulnerabilities (CVE-2023-46805 and CVE-2024-21887) for initial access. The attackers have used a custom dropper to install a malicious Java Servlet filter (BRICKSTEAL) in memory, avoiding detection. The attackers have modified init.d, rc.local, or systemd files to ensure persistence on appliances. The attackers have targeted Windows environments in Europe since at least November 2022. The attackers have been linked to other related Chinese threat actors besides UNC5221. The campaign has been monitored by Mandiant since March 2025. The attackers have targeted downstream customers of compromised SaaS providers. The attackers are believed to be analyzing stolen source code to identify zero-day vulnerabilities in enterprise technologies. The attackers use a delay timer to lie dormant on infected systems until a hard-coded date. The malware employs Garble, an open-source tool, for code obfuscation to hide function names, structures, and logic. Brickstorm has been found on VMware vCenter and ESXi hosts, often deployed prior to pivoting to these systems. The attackers use legitimate cloud services like Cloudflare Workers or Heroku for C2 communications. The attackers use dynamic domains like sslip.io or nip.io that point directly to the C2 server’s IP. The attackers favor appliance and management-plane compromise, per-victim obfuscated Go binaries, delayed-start implants, and Web/DoH C2 to preserve stealth. The attackers harvest and use valid high-privilege credentials to appear as routine administrator tasks. The attackers deploy in-memory servlet filters, remove installer artifacts, and embed delayed-start logic to limit forensic traces. The attackers abuse virtualization management capabilities, such as cloning VMs to extract credential stores offline. The attackers deploy an in-memory Java Servlet filter on vCenter to intercept and decode web authentication to harvest high-privilege credentials. The attackers use a SOCKS proxy on compromised appliances to tunnel into internal networks for interactive access and file retrieval.

APT41, a China-linked threat group, has been conducting targeted phishing campaigns against U.S. trade officials, law firms, think tanks, and academic organizations. The attacks, impersonating U.S. officials and organizations, aim to steal sensitive data related to U.S.-China trade negotiations. The campaigns have been ongoing since at least January 2025, with a surge in activity observed in July and August 2025. The U.S. House Select Committee on China has issued a formal advisory warning about these activities, linking them to a Beijing-led effort to influence policy deliberations. The FBI is investigating these attacks. The phishing emails impersonate U.S. officials, including Rep. John Robert Moolenaar, and organizations such as the U.S.-China Business Council, to trick recipients into opening malicious attachments or links. The attacks exploit software and cloud services to evade detection and exfiltrate data. The goal is to gain an advantage in trade and foreign policy negotiations. The Chinese embassy has denied the allegations, stating that China opposes cyber attacks and cyber crime. APT41 has been linked to various sophisticated campaigns targeting multiple sectors, including logistics, utility companies, healthcare, high-tech, and telecommunications.

Threat actors are exploiting HTTP client tools like Axios and Microsoft's Direct Send feature to create highly efficient phishing campaigns targeting Microsoft 365 environments. These attacks, which began in July 2025, initially targeted executives and managers in finance, healthcare, and manufacturing sectors, but have since expanded to all users. The campaigns use compensation-themed lures to trick recipients into revealing credentials and bypassing multi-factor authentication (MFA). The abuse of Axios has surged, accounting for 24.44% of all flagged user agent activity from June to August 2025. The attacks leverage Axios to intercept, modify, and replay HTTP requests, capturing session tokens or MFA codes in real-time. This method allows attackers to bypass traditional security defenses and conduct phishing operations at an unprecedented scale. Additionally, a phishing-as-a-service (PhaaS) offering called Salty 2FA has been discovered, which steals Microsoft login credentials and sidesteps MFA by simulating various authentication methods. Salty 2FA uses advanced features such as subdomain rotation, dynamic corporate branding, and sophisticated evasion tactics to enhance its phishing campaigns. It also abuses legitimate platforms to stage initial attacks and uses Cloudflare Turnstile for secure CAPTCHA replacement. Salty2FA campaigns have been active since late July 2025 and continue to this day, generating dozens of fresh analysis sessions daily. The campaigns target industries including finance, healthcare, government, logistics, energy, IT consulting, education, construction, telecom, chemicals, industrial manufacturing, real estate, and consulting.