Malware

Vidar

3 mentions in 7 days · 8 in 30 days · 8 total · first seen Aug 20, 2026 · last 5d ago

Timeline8 articles

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 BlogSep 10, 16:00 UTC · 5d agoPhishing & fraud in the wild1

The Top 4 Threats We Found by Investigating Every Alert for a Quarter

Prophet Security's quarterly threat report finds identity attacks made up roughly half of confirmed malicious activity, with stolen authenticated sessions bypassing conditional access controls.

Between May 1 and July 31, 2026, Prophet Security investigated every alert in customer environments immediately on arrival; about 7% of completed investigations were confirmed malicious. Direct account/session attacks made up roughly 18% of confirmed activity, with replayed authenticated sessions bypassing conditional access since no re-authentication occurs. Infostealer activity affected about a quarter of investigated organizations, mostly delivered via browsers through compromised websites, malicious ads, sponsored search results and ClickFix fake CAPTCHA gates, with payloads including Lumma Stealer, Vidar, HijackLoader and AsyncRAT. Credential phishing was the largest category at about 28%, with adversary-in-the-middle relays revealed by seconds-long MFA approvals from distant countries and MFA fatigue attacks exploiting automatic unlock policies.

BleepingComputerSep 10, 14:00 UTC · 5d agoThreat actor in the wild

Infostealer Logs Expose Replayable AI Tokens That Can Bypass MFA

Okta finds infostealer logs contain thousands of replayable AI session tokens and API keys, letting criminals bypass MFA and access services from Google, Anthropic and OpenAI.

Okta analyzed a 7 GB infostealer dump from August 2, 2026 covering 5,871 infected machines in 162 countries and found 555 of 44,791 JWTs related to AI services, plus 1,843 unexpired JWTs and JWEs (largely set by OpenAI via NextAuth.js) and 24 still-valid API keys for Google Gemini, OpenAI, Groq and OpenRouter. Valid session tokens and API keys can be replayed with anti-detect browsers like Camoufox to bypass credential and MFA checks, fueling an underground market for AI account access known as LLMjacking, where attackers rack up victims' AI compute bills. Some 17.7% of the JWTs contained plaintext PII usable for social engineering. Google's GTIG reported growing buyer demand for Claude, Gemini, Cursor and Devin credentials, and Mandiant handled an incident where an actor used an exposed GitHub PAT to deploy unauthorized AI infrastructure and scale high-performance compute.

The Hacker Newsupdated Sep 10, 10:36 UTC · 5d agofirst Sep 9, 14:23 UTC · 6d agoThreat actor in the wild 4 sources1

Infostealers Are Hijacking Claude Sessions and Draining Subscriptions

Infostealers hijacked active Claude sessions to bypass 2FA, drain paid usage and run unauthorized charges; Anthropic is revoking sessions and refunding.

Anthropic confirmed that infostealer malware on user machines stole active Claude login sessions, letting attackers bypass passwords, MFA, and SSO and drain paid usage and run unauthorized charges. Affected families identified on Windows include Vidar, LummaC2, StealC, RedLine, and Acreed, plus Atomic Stealer on a small number of Macs; the malware typically arrived via unofficial downloads or malicious apps. Anthropic signed users out, removed saved payment cards, revoked affected sessions, and is refunding unauthorized charges, noting phones and tablets were not involved.

Security AffairsAug 31, 09:17 UTC · 15d agoMalware in the wild

Anthropic locks out Claude users after infostealers hijack login sessions

Anthropic invalidated Claude sessions compromised by infostealers such as Vidar, Lumma and Atomic Stealer, which steal browser cookies to bypass 2FA.

Anthropic began locking users out of Claude accounts after infostealer malware stole browser session cookies, letting attackers replay logins and bypass two-factor authentication. Identified malware includes Vidar, Lumma (LummaC2), StealC, RedLine and Acreed on Windows and Atomic Stealer (AMOS) on a small number of Macs. Anthropic signed affected users out, removed saved payment methods and refunded unauthorized charges. One affected user traced the infection to a pirated game downloaded from a Russian underground forum; the company advised victims to remove the malware before resetting passwords and re-enabling 2FA.

Help Net SecurityAug 31, 00:00 UTC · 15d agoData breach in the wild1

Week in review: Records allegedly stolen from Azure tenants, Medusa ransomware hits 500+ orgs

Week in review: Medusa ransomware hit 500+ orgs per CISA, millions of Azure tenant records allegedly stolen, SafePal and French tax authority breaches disclosed.

Help Net Security's weekly roundup covers the FBI, CISA, and HHS joint advisory update reporting Medusa ransomware has breached more than 500 organizations since June 2021, and threat actor TheHatman's claim of millions of employee records stolen from Azure tenants of Fortune 500 firms including McDonald's, Vodafone, Kyndryl, and Tata Consultancy Services, per Hudson Rock. It also covers the SafePal breach affecting 39,798 customers, France's DGFiP breach exposing data on 678,000 individuals, and UT San delaying its fall semester after a cyberattack. Security items include critical unauthenticated GitLab flaw CVE-2026-19478, an actively exploited patched macOS Screen Sharing flaw deploying a cryptominer, US charges against 17 Mabna Institute Iranian hackers over 31TB of stolen academic data, and Google Mandiant's AI agents finding 100+ high-severity vulnerabilities.

Help Net SecurityAug 23, 00:00 UTC · 23d agoData breach in the wildCVE-2026-19478

Fake Conferences, OAuth and WhatsApp: Inside Russia’s New Espionage Tactics

Google tracks three Russia-linked espionage clusters abusing OAuth, app passwords, and device code phishing against Western researchers and diplomats.

Google's Threat Intelligence Group documented three suspected Russia-linked clusters, UNC6293, UNC7005, and UNC5976, abusing legitimate authentication flows. UNC6293, a likely APT29/ICE RELIC sub-cluster, impersonates US State Department officials in app password and OAuth phishing targeting fewer than five victims at a time. UNC7005, tracked by Microsoft as STORM-2945, spoofs the GLOBSEC conference, runs device code phishing against Microsoft and WhatsApp accounts, and deploys VIDAR and AtomicStealer infostealers. Targets include researchers, academics, diplomats, think-tank analysts, and defense personnel in Europe and the United States.

Security AffairsAug 21, 11:11 UTC · 25d agoThreat actor in the wild1

Fake Gemini installer delivers Vidar infostealer via Google Colab lure

Attackers used a fake Google Gemini installer hosted on Google Colab to deliver a Go-compiled Vidar infostealer that stole browser credentials from an EMEA company.

Darktrace investigated an EMEA company infection where the top search result for a Gemini-related filename pointed to a Google Colab page that redirected to a fake 'Windows Software Hub' hosting a malicious executable. The ZIP contained a README instructing victims to run the file as administrator and add it to antivirus exceptions, delivering a newer Go-compiled Vidar variant that used dtm[.]kijangturbo88[.]top over Telegram-based infrastructure. The malware stole browser credentials and other sensitive data; Darktrace's Autonomous Response blocked the C2 and quarantined the device.

Help Net SecurityAug 20, 00:00 UTC · 26d agoMalware in the wild

Related CVEsby mentions

CVE-2026-194789.16%
Unauthenticated GraphQL Code Injection in GitLab CE/EE Enables Data Tampering
GitLab has patched a critical (CVSS 9.1) code injection flaw (CWE-94) in how GitLab Community Edition (CE) and Enterprise Edition (EE) process GraphQL directives. Under certain conditions, an unauthenticated remote attacker can abuse a GraphQL directive to modify or delete public projects and user data on affected instances, requiring no privileges or user interaction; the impact is to integrity and availability, not confidentiality. Affected versions span all GitLab CE/EE releases from 18.2 before 18.11.11, 19.0 before 19.0.8, 19.1 before 19.1.6, and 19.2 before 19.2.4, which covers self-managed installations as well as the same codebase that powers the GitLab.com SaaS. News reports indicate the flaw came under active exploitation within days of disclosure, and EPSS assigns a 5.8% probability of exploitation within 30 days (93rd percentile). It is not yet listed in CISA's KEV catalog and no public proof-of-concept is known, but defenders should treat it as an actively exploited, unauthenticated, high-impact issue.
· GitLab CE all versions from 18.2 before 18.11.11, 19.0 before 19.0.8, 19.1 before 19.1.6, and 19.2 before 19.2.4 · GitLab EE all versions from 18.2 before 18.11.11, 19.0 before 19.0.8, 19.1 before 19.1.6, and 19.2 before 19.2.4mass

Appears with

vendor Microsoft 3 vendor Google 3 product Claude 3 organization Anthropic 3 vendor Anthropic 2 malware Acreed 2 malware Atomic Stealer 2 ai model Claude 2 organization Google Threat Intelligence Group 2 malware RedLine 2 malware Lumma Stealer 2 product Microsoft 365 2 malware StealC 2 product ChatGPT 2 malware AsyncRAT 1 threat actor SocGholish 1

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