ZeroHour
DashboardNewsCVEsExploitsIncidentsAIBriefAnalyticsEntitiesWatchlistIOCsAsk the feedSourcesFeeds & APIKiosk mode

Search: “Microsoft Defender Experts”

35 stories

Searchkeywordsmart Sortlatesthotimportancerelevance
DomainAllCyberAIWindow24h3d7d30dAllIn the wildImportant onlyShow duplicates
CategoryAllExploit / PoC 184Ransomware 155Vulnerability 44Data breach 37Threat actor 32Policy & legal 31Malware 23Phishing & fraud 4Advisory 1AI safety & security 1Model release 1
SeverityAllcritical 476high 35medium 1low 0info 1

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.

Microsoft Security Blog · 15d agoThreat actor in the wild1

Counterfeit installers turn routine software downloads into enterprise breaches

Microsoft warns of a multi-sector campaign using counterfeit download sites for Edge, Kaspersky and Razer to deliver trojanized installers with persistent implants.

Microsoft Defender Experts tracked a campaign breaching organizations in healthcare, manufacturing, gaming, technology, logistics, government, and education via spoofed vendor download pages, often using .com.cn and .hl.cn domains. Installers keep the same filename while their hash changes on every download, indicating server-side payload generation that defeats file-based detection. The chain abuses msiexec.exe and scheduled tasks for persistence, adds Defender exclusions, deletes shadow copies, and disables Windows Update, with some hands-on-keyboard activity. The activity is consistent with the publicly reported Silver Fox (Yinhu) campaign, though Microsoft has not attributed it to a nation-state actor.

CSO Online · 13d agoThreat actor in the wild1

September 2026 Patch Tuesday roundup: Plugs for two zero day holes among almost 1,000 fixes in Windows

Microsoft's September 2026 Patch Tuesday ships 964 fixes including two exploited Windows zero-days (CVE-2026-85880, CVE-2026-81963) and a wormable DNS RCE.

Microsoft's September 2026 Patch Tuesday includes 964 Microsoft vulnerabilities requiring customer action, a record attributed to AI-assisted bug discovery, plus 174 third-party/open-source and 23 Chromium/Edge CVEs. Two zero-days are exploited in the wild: CVE-2026-85880, a Windows ALPC heap overflow enabling AppContainer sandbox escape and privilege escalation, and CVE-2026-81963, a Windows Update Stack escalation to SYSTEM. CVE-2026-69730, an unauthenticated Windows DNS RCE, is not yet exploited but Microsoft expects exploitation, and roughly 20 bugs could be wormable. Separately, SAP issued a critical CVSS 10.0 fix for the EPP component used in S/4HANA and NetWeaver.

CSO Online · 8d agoVulnerability in the wildCVE-2026-85880CVE-2026-81963CVE-2026-69730+2 CVEs1

Detect and disrupt AI-themed attacks with Microsoft Defender

Microsoft Threat Intelligence reports criminal campaigns impersonating ChatGPT, Copilot, Claude, and DeepSeek in phishing, AiTM, and malvertising attacks reaching 100,000 emails daily.

Microsoft Threat Intelligence observed a growing set of campaigns that abuse trust in popular AI brands: a ChatGPT-themed phishing campaign sent up to 100,000 emails in one day to steal payment card data, and a Claude-themed campaign used adversary-in-the-middle techniques to harvest credentials and access tokens. Other campaigns included malvertising for a fake AI Windows plugin delivering the Vidar stealer and fraudulent DeepSeek installers distributed via GitHub. Initial access broker Storm-3075 used AI-themed malvertising to distribute payloads for multiple downstream actors, and Microsoft notes the AI services themselves were not compromised. Microsoft also details Defender protections such as Safe Links, Safe Attachments, and attack disruption against these multi-stage lures.

Microsoft Security Blog · 6d agoPhishing & fraud in the wild1

Microsoft posts nearly 1,000 bugs for Patch Tuesday as CISA warns two being exploited

CISA confirms exploitation of two Windows zero-days among 973 Microsoft patches; 22,000 Exchange servers remain unpatched.

Microsoft's September Patch Tuesday sets a record with 973 vulnerabilities, and CISA confirms CVE-2026-81963 and CVE-2026-85880 are being exploited, giving federal agencies until September 22 to patch. Nightwing estimates over 22,000 corporate Exchange servers are unpatched against weaponized exploit code. Analysts describe CVE-2026-81963 as an early link in ransomware chains where phishing leads to privilege escalation, and note year-to-date Microsoft disclosures exceed 2,600 bugs.

The Record · 8d agoExploit / PoC in the wildCVE-2026-81963CVE-2026-85880

Threat Brief: Ongoing Russia and Ukraine Cyber Activity

Ukrainian government sites were defaced via OctoberCMS CVE-2021-32648 while Microsoft-attributed actor DEV-0586 deployed destructive WhisperGate malware.

Unit 42 tracks January 2022 attacks against Ukrainian government websites that were defaced or made inaccessible, which Ukraine attributed to Russia. Attackers exploited CVE-2021-32648, an account takeover flaw in OctoberCMS prior to 1.0.472, by submitting a boolean true as the password reset code to bypass validation. Separately, WhisperGate malware, attributed by Microsoft to DEV-0586, disabled Windows Defender and corrupted files across multiple Ukrainian organizations, using a ransomware-appearing first stage and an HTTPS-beaconing second stage with LOLBINs and anti-analysis techniques.

Palo Alto Unit 42 · Aug 17, 2026Threat actor in the wildCVE-2021-326481

Anthropic caught Russia-linked spies using Claude in hacking operations

Anthropic disrupted Russia-linked APT29 using Claude in espionage against 20+ organizations, including Ukrainian government targets and a military drone maker whose vision SDK was stolen.

Anthropic's threat report covering December 2025 to August 2026 attributes the campaign to Midnight Blizzard (APT29/Cozy Bear, Storm-2945), which it links to Russia's SVR. The group compromised hotel Wi-Fi providers, altered DNS records to redirect travelers, accessed mailboxes at two drone-component manufacturers, and stole a proprietary SDK for a drone vision system, which it reverse-engineered using Claude. The group also used Claude to monitor whether security products detected its implants and to modify and redeploy flagged artifacts. The report also covers ShinyHunters affiliates using AI for credential scanning and extortion, a Chinese-speaking group's autonomous zero-day research, and a French-speaking hacktivist.

The Recordupdated · 15h agofirst · 5d agoThreat actor in the wild 18 sources

More than 200 victims of Medusa ransomware identified over the last year, CISA says

CISA and FBI update Medusa ransomware advisory, reporting more than 500 total victims and warning the gang operationalizes newly disclosed exploits within 24 hours.

CISA and the FBI updated their March 2025 advisory, stating Medusa actors had hit more than 500 victims as of April 2026, up from 300 in 2025, with a focus on healthcare and critical infrastructure. The agencies say Medusa rapidly adopts newly announced exploits, sometimes using them up to a week before public vulnerability disclosure, but does not develop its own zero-days, preferring access obtained from unknown sources. The gang moved to an affiliate model in 2023, offers up to $1 million for exclusive initial access brokers, and uses credential stealers plus legitimate remote access tools including AnyDesk, Atera, ConnectWise and Splashtop. No new victims have appeared on its leak site since April, after the shutdown of the University of Mississippi Medical Center drew significant law enforcement attention.

The Record · 29d agoRansomware in the wild1

August 2026 CVE Landscape

Insikt Group catalogs 73 high-impact August 2026 CVEs (43 Very Critical), including PaperCut, Zimbra, and Metabase flaws actively exploited or weaponized.

Recorded Future's Insikt Group identified 73 high-impact vulnerabilities in August 2026, 43 rated Very Critical, spanning 45 vendors with Microsoft accounting for roughly 11%. 31 vulnerabilities surfaced via CISA's KEV catalog, with others validated via open sources, vendor telemetry, and honeypot data. New Nuclei detection templates were released for CVE-2025-62593 (Ray), CVE-2026-72898 (Metabase), and CVE-2026-9198 (IBM Langflow). The report also highlights two AI-assisted operations: UAT-10147 exploited Zimbra, AjaxPro, Nacos, and Telerik servers before using DeepAudit and PentestGPT post-compromise, while a separate Chinese-speaking actor weaponized Hermes Agent and DeepSeek in a failed attempt.

Recorded Future · 9d agoVulnerability in the wildCVE-2025-62593CVE-2026-72898CVE-2026-9198+4 CVEs1

Risky Bulletin: Russia tells data centers to deploy drone defenses

Russia ordered data center operators to deploy drone strike defenses under a Putin decree allowing temporary state takeover of unprotected critical infrastructure.

The Russian government instructed data center operators to deploy protections against drone strikes under a presidential decree signed by Putin that allows temporary state administration of critical infrastructure operators failing to defend against Ukrainian hacks and drone strikes. Although data centers are not formally critical infrastructure in Russia, the decree applies to them because other sectors depend heavily on cloud services; Russia has more than 180 data centers, over 80% in the European region within range of Ukrainian strikes. The digest also reports a Dropbox breach affecting nearly 5,000 accounts via the Lenovo ID integration, spyware attacks on at least 14 Serbians using NoviSpy or Pegasus, and a password recovery attack targeting hundreds of thousands of X accounts tied to the new X Money service. Other items include a 14-hour compromise of Coder's Cloudflare infrastructure delivering malicious Terraform modules, donor data breaches at Davayte and You Are Not Alone via the Stripe/WooCommerce integration, a $2.5M Aquifer crypto heist, and a TVING breach exposing data of almost 40 million accounts.

Risky Business News · 13d agoPolicy & legal