Search: “Windows Defender Application Control”
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Counterfeit installers to system compromise: Tracking a deceptive software download campaign
Microsoft tracks a counterfeit software-installer campaign compromising multinationals' China operations, moderately linked to the Silver Fox (Yinhu) actor.
Microsoft Defender Experts is tracking an active campaign using spoofed software download sites for brands such as Razer, Kaspersky, Microsoft Edge, Calibre, and Baidu Netdisk on .com.cn and .hl.cn domains, delivering installer archives whose hashes change per download, indicating server-side payload generation. The implants establish persistence, weaken security protections, and communicate with attacker-controlled infrastructure, with confirmed compromises across healthcare, manufacturing, gaming, technology, logistics, government, and education. Microsoft assesses with moderate confidence that the activity matches the publicly reported Silver Fox (Yinhu) fake software campaign; it has not attributed it to a nation-state actor.
Fake Software Installers Disable Windows Update and Weaken Microsoft Defender
Fake software-download sites distribute installers that disable Windows Update and weaken Defender, attributed to China-linked cluster Silver Fox.
Microsoft says an active campaign uses counterfeit vendor websites on .com.cn and .hl.cn infrastructure with Chinese-language lures to deliver server-side generated installers that establish scheduled-task persistence, add Defender exclusions, delete shadow copies, and stop services including wuauserv, UsoSvc, uhssvc and WaaSMedicSvc. Victims span healthcare, manufacturing, gaming, technology, logistics, government and education, primarily China-based operations of multinationals and Chinese-speaking users. Microsoft assesses with moderate confidence the activity matches the Silver Fox (Yinhu) cluster, historically tied to Gh0st RAT and ValleyRAT, with C2 over non-standard ports like 5090 and 7088-7090 via domains iualef[.]net and oijfwe[.]net. Kaspersky separately detailed a QN Wallpaper DLL-sideloading chain delivering ValleyRAT.
ThreatsDay: CEO Phishing Kits, 5K Dropbox Account Hacks, OAuth Traps + 17 More Stories
Microsoft warns of Teams IT-impersonation intrusions deploying Node.js implants; Spring Ring vishing hit 150+ employees across 10 companies; The Gentlemen ransomware claims 683 victims.
Microsoft warned of a human-operated campaign abusing Teams external collaboration to impersonate IT help desk staff, deploy malicious MSI packages staging Node.js runtimes and obfuscated JavaScript implants, then pivot to domain controllers over WinRM. Unit 42 documented the Spring Ring vishing operation targeting over 150 employees across at least 10 companies using 26 attacker identities, including an NTLM relay variant against domain controllers. Sophos reported The Gentlemen ransomware (Gold Sherwood) reached 683 total victims by end of July 2026, adding 169 in July, with a playbook using BYOVD-based EDR killers and backup tampering. Group-IB found the Outsider phishing-as-a-service platform created 700+ new phishing pages within a month despite law enforcement takedowns.
VU#687587: AOMEI Backupper amwrtdrv.sys local privilege escalation vulnerability allows arbitrary writes to physical disks
AOMEI Backupper 8.4.0 driver flaw CVE-2026-12780 lets unprivileged users write physical disks and execute UEFI code, bypassing HVCI and EDR.
CERT/CC issued VU#687587 for CVE-2026-12780, an incorrect permission assignment (CWE-732) in the amwrtdrv.sys kernel driver shipped with AOMEI Backupper 8.4.0. The driver exposes a world-accessible device object without a security descriptor, allowing any unprivileged user to write arbitrary physical disk sectors; with Secure Boot disabled, an attacker can modify the GPT and inject a UEFI payload that executes before the OS loads, bypassing HVCI, EDR, Windows Defender and Hyper-V isolation. On TPM-only BitLocker configurations the attack can capture Volume Master Key material during pre-boot. AOMEI has shipped patches; users who cannot update should uninstall the software or disable the amwrtdrv.sys service, and enabling Secure Boot adds defense in depth.
Breeze Comet Executes Hundreds of Fraudulent Transactions via Brazilian Payment Systems
Google/Mandiant profile Breeze Comet, a Brazil-based e-crime group executing fraudulent Pix and STR payment transactions at banks, retailers, and fintechs.
Google Threat Intelligence Group and Mandiant describe Breeze Comet (formerly UNC5669), a financially motivated threat actor active since September 2023 targeting Brazilian financial services, retail, and e-commerce. The group gains access via password spraying, vishing impersonating IT support to install RMM tools like AnyDesk, WhatsApp social engineering, and exploitation of vulnerable JBoss AS servers for web shell deployment. It uses compromised government websites as C2, deploys the Rust-based COBALTSPIN tunneler and multiple custom backdoors (LIGHTPAINT, MILDFROST, KICKPLATE, BOATBEAM), then clears logs after executing hundreds of fraudulent transactions through Pix, STR, and Boleto payment systems. At least one heist yielded tens of thousands of dollars, with infrastructure suggesting expansion toward Latin America and Africa.
Iranian spies hit Windows machines with Chosen Brick data-stealing malware
FBI, UK NCSC, and Dutch AIVD warn Iranian intelligence uses Chosen Brick spyware against dissidents, stealing contacts, emails, and messaging data.
A joint advisory from the FBI, UK NCSC, and Dutch AIVD says Iranian state cyber actors have used the Chosen Brick Windows malware since at least 2025 to surveil dissidents, activists, and journalists. Attacks begin with heavily researched WhatsApp and Telegram messages impersonating trusted contacts, tricking victims into opening fake installers resembling Pictory, RunwayML, Norton Antivirus, Telegram, Adobe Flash Player, and KeePass. The malware persists via the HKCU Run registry key, adds Microsoft Defender exclusions, uses victim-specific Telegram bots for C2, captures screen and audio, steals emails and Telegram/WhatsApp data, and can wipe systems.
Iranian hackers use CHOSEN BRICK Windows malware to spy on targetsnew
Iranian state-linked hackers use CHOSEN BRICK Windows malware, spread via Telegram and WhatsApp social engineering, to spy on dissidents and journalists worldwide.
US, UK, and Dutch cyber agencies with the FBI issued a joint advisory on Iranian state-linked hackers deploying a Windows malware strain called CHOSEN BRICK against dissidents, activists, and journalists, primarily in the US, UK, and Netherlands. Attacks begin with messages on WhatsApp or Telegram impersonating trusted contacts or technical support, tricking victims into running malicious files disguised as apps such as Pictory, RunwayML, Norton Antivirus, Telegram, and KeePass. The malware persists via Registry Run keys, adds Microsoft Defender exclusions, and uses a per-victim Telegram bot for command-and-control while stealing email, Telegram and WhatsApp data, screenshots, and audio. Stolen data is exfiltrated via Telegram or cloud services like VultrObjects and StorjShare, and sometimes appears on pro-Iranian leak sites, increasing physical risk for dissidents abroad.
Iranian cyber targeting of dissidents, activists and journalists
UK NCSC, FBI, and Dutch AIVD expose CHOSEN BRICK spyware used by Iranian state actors against dissidents, activists, and journalists worldwide.
A joint advisory from the UK NCSC, FBI, and Dutch AIVD details CHOSEN BRICK, a Windows spyware family used by Iranian state cyber actors since at least 2025 against dissidents, activists, and journalists in the UK, US, and Netherlands. Actors build rapport on WhatsApp and Telegram impersonating known contacts or platform support, then deliver disguised payloads resembling apps such as Telegram, Norton, RunwayML, or fake MRI results. The malware persists via HKCU Run registry keys, adds Microsoft Defender exclusions, and uses a unique Telegram bot C2 per victim. Capabilities include screen capture, microphone recording, process enumeration, email and messaging data theft, file deletion, and system wiping; victim data has appeared on pro-Iranian leak sites.