ZeroHour

Search: “session”

1,669 stories

BigBear 2.0 phishing campaign hijacks Microsoft 365 sessions after MFA

CloudSEK uncovered BigBear 2.0, a PhaaS operation that captured 4,148 Microsoft 365 session cookies, hijacking authenticated sessions after MFA via AiTM proxy.

CloudSEK infiltrated the BigBear 2.0 phishing-as-a-service panel in June, finding 5,137 credential records tied to 461 organizations in over 40 countries, including 4,148 captured session cookies and 474 completed post-MFA logins. The operation, built on Evilginx2, uses an attacker-controlled reverse proxy to steal authenticated session cookies and residential proxies to defeat location-based Conditional Access checks, while custom code disables FIDO2/WebAuthn on phishing pages. At least five affiliates operated 42 VPS nodes, with IT services and managed service providers the most targeted sector.

CSO Online · 8d agoPhishing & fraud in the wild1

BigBear 2.0 Evilginx2 Phishing Campaign Bypasses Microsoft 365 MFA With Session Cookie Theft

CloudSEK identified BigBear 2.0, an Evilginx2-based AiTM phishing operation stealing Microsoft 365 MFA session cookies, hitting 461 organizations across 40-plus countries.

The campaign proxies Microsoft sign-in pages to capture credentials and authenticated session cookies, enabling session replay into email, Teams, SharePoint, OneDrive, and connected SSO applications. CloudSEK's June 2026 discovery found 5,137 stolen records, 1,032 passwords, and 4,148 session cookies tied to 3,331 victim IPs, linked to operator 'General Boss' across 42 VPS nodes. The operation targeted IT services and managed service providers, used country-matched residential proxies, and involved at least five affiliates.

Cyber Security News · 8d agoPhishing & fraud in the wild1

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 Affairs · 16d 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 Security · 16d agoData breach in the wild1

Mirage2FA Surge Hits 4,500 US and EU Companies, Abusing Microsoft 365 Login Flows

Mirage2FA phishing-as-a-service campaign hit ~4,500 organizations, mostly US, stealing Microsoft 365 passwords and session cookies to bypass 2FA.

ANY.RUN research links the Mirage2FA phishing-as-a-service toolkit to 4,532 unique organization email domains between 2024 and 2026, with the US accounting for 63.7% of victims. The kit uses adversary-in-the-middle login flows to harvest credentials and session cookies, bypassing MFA on Microsoft 365 accounts. Researchers recorded more than 9,000 potential compromise events and estimated 48% of targeted email addresses were potentially compromised. Hijacked sessions extend to SSO-connected services, enabling impersonation, fraud and further compromise.

The Hacker News · 22d agoPhishing & fraud in the wild

Impersonating IT support: how threat actors turn a remote session into enterprise-wide access

Microsoft details Teams IT-support impersonation campaigns deploying Node.js implants, AD reconnaissance, and WinRM lateral movement toward domain controllers.

Microsoft Threat Intelligence describes a human-operated campaign where attackers impersonate IT/helpdesk staff via Microsoft Teams external collaboration, talk users into granting remote sessions, and use RMM tools for interactive access. During the session they run PowerShell to silently install a malicious MSI that stages a portable Node.js runtime and obfuscated JavaScript implant for C2, executing follow-on payloads via rundll32. Operators then perform host and Active Directory reconnaissance, capture desktop screenshots, and pivot via WinRM on port 5985 to domain controllers and certificate authorities. The hands-on-keyboard chain, which can precede data theft and ransomware, blends into normal operations by relying on Teams, Quick Assist, msiexec, and Node.js; Microsoft shares hunting and mitigation guidance.

Microsoft Security Blog · 13d agoThreat actor in the wild

Passkey-themed social engineering leads to identity and cloud compromise

Microsoft tracks ongoing cloud intrusions where passkey-themed helpdesk lures enable AiTM credential theft, MFA persistence, and SharePoint data theft.

Microsoft Security Research is tracking active cloud-based intrusions, observed since May 2026, that begin with helpdesk impersonation calls and SMS lures urging urgent passkey, MFA, or SSO updates. The lures lead to adversary-in-the-middle phishing or device-code authentication flows that capture credentials and session tokens or grant actor access, after which the actors add authentication methods, conduct Microsoft Graph reconnaissance, and download SharePoint and OneDrive content via REST APIs. Phishing domains embed victim organization names as subdomains (e.g., contoso.add-passkey[.]com), are often registered with Nicenic, and go operational within hours. Microsoft advises revoking sessions and removing unauthorized authentication methods for confirmed compromises.

Microsoft Security Blog · 7d agoThreat actor in the wild2

iAuthFlow v2: The $10,000 Phishing Toolkit That Survives Your Password Reset

Abnormal Security details iAuthFlow v2, a $10,000 phishing kit that enrolls attacker-controlled passkeys on Google accounts, persisting through password resets.

Abnormal Security analyzed iAuthFlow v2, a phishing toolkit sold on a Russian-language cybercrime forum for a $10,000 base price with additional capability modules sold separately. Using a browser-in-the-middle relay behind a trycloudflare.com subdomain with valid TLS, it captures Google logins and uses the authenticated session to enroll an attacker-controlled passkey within six seconds of login. Because the passkey persists after password changes and session revocation, operators regain mailbox access even after victims reset credentials. The build examined targets Google, while the seller advertises versions for Microsoft, iCloud, and LinkedIn.

Security Affairs · 23d agoPhishing & fraud1

ChatGPT flaw lets attackers pull Gmail data across accounts via a hidden channel

Check Point found a ChatGPT flaw letting attackers read victims' Gmail and connected-app data via hidden cross-session instructions; OpenAI patched it.

Check Point Research discovered a covert cross-account command channel in ChatGPT's code execution environment, where containers meant to be isolated shared metadata through an internal service based on JFrog Artifactory. In a proof of concept, a victim's session was tricked into retrieving Gmail email data and relaying it to an attacker-controlled session during an ordinary-looking interaction, with reach extending to any connected apps the session was authorized for, including Google Drive, Microsoft Teams, and GitHub. OpenAI fixed the issue and decommissioned the internal service; the same shared infrastructure was also involved in the separately disclosed Hugging Face compromise, though via different techniques.

CSO Online · 7d agoAI safety & security

KREMLIN Banking Malware Bypasses Chrome Security to Steal Banking Sessions

Elastic Security Labs details KREMLIN, a Brazilian banking malware that implants malicious Chrome and Edge extensions by forging Chromium integrity values to steal banking sessions.

Elastic Security Labs tracks the KREMLIN banking malware operation as REF9334, active since at least May 2025 across seven campaigns primarily targeting 12 Brazilian banks. The malware is installed by a victim-run JavaScript loader, achieves scheduled-task persistence, and side-loads a malicious DLL via SentinelOne's SentinelMemoryScanner.exe. It modifies Chrome and Edge Secure Preferences files, enables developer mode, and regenerates Chromium MAC values to silently install extensions, while extracting browser encryption material including the newer App-Bound OSCrypt key. An Ethereum smart contract serves as a dead-drop resolver for C2 config; Elastic disrupted over 1,500 infections via a canary domain.

GBHackers · 15h agoMalware in the wild 2 sources

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 News · 7d agoThreat actor in the wild1

The Coding-Agent Trap: When a "Free" LLM Endpoint Is the Adversary, (Mon, Aug 31st)

A SANS honeypot caught a real coding-agent session routed to a rogue "free" LLM endpoint, exposing a Windows user's transcript and tool outputs.

A SANS analyst describes how an internet-exposed inference honeypot was discovered, relabeled with sought-after model names like DeepSeek, and enrolled in infrastructure serving "free" LLM backends. On 2026-08-30 an opencode terminal coding agent sent an 88-message, 224 KB transcript 210 times in 91 seconds via a China Unicom relay, exposing directory listings, tool outputs and read file portions. The analyst frames tool-enabled agents treating model endpoints as trusted control planes as a novel risk — a "rogue model endpoint" that could request tool executions on the user's machine.

SANS Internet Storm Center · 16d agoAI safety & security1

Attacker Hijacks AI Coding Assistant Session, Spreads Shai-Hulud Across About 100 Repositories

Mandiant says an attacker hijacked an AI coding-assistant session at a SaaS provider and spread the Shai-Hulud worm across roughly 100 repositories, stealing secrets.

Mandiant's September 2026 report describes an attacker hijacking an active AI coding-assistant session at an unnamed SaaS provider, then getting a poisoned package recommendation accepted and installing an infostealer via a malicious PyPI package. The attacker stole GitHub OAuth tokens, deployed the self-spreading Shai-Hulud worm across approximately 100 internal repositories, and stole repository secrets and product source code. Poisoning a package in the company's official namespace caused a second employee to pull the compromised version and become infected. Mandiant recommends verifying AI-recommended dependencies against checksums and allowlists, keeping secrets out of extension reach, and routing dependency traffic through internal repositories.

The Hacker News · 7h agoData breach in the wild

The Shared Clipboard Inside the Sandbox: Cross-Account Data Leakage in ChatGPT

Check Point discovers cross-account data leakage in ChatGPT: isolated code-execution containers communicate via shared JFrog Artifactory, enabling covert Gmail exfiltration.

Check Point Research found a covert bidirectional channel between ChatGPT code-execution containers belonging to different accounts, which were supposed to be isolated from each other and the public internet. Both could reach the same internal JFrog Artifactory instance used for package delivery, whose exposed Item Management API allowed a 'shared clipboard' between containers. In a proof of concept, a hidden instruction in a shared conversation made ChatGPT retrieve email data from the victim's connected Gmail account and send it to the attacker's account while the victim received a normal answer. The same channel could exfiltrate conversation history and session files; OpenAI recently described a similar isolation weakness in its postmortem of the Hugging Face incident.

Check Point Research · 8d agoAI safety & security1

BigBear phishing crew nets thousands of Microsoft 365 credentials

CloudSEC accessed the BigBear 2.0 phishing panel, finding 5,137 stolen Microsoft 365 records across 461 organizations, including 474 MFA-bypassed sessions.

CloudSEC researchers got inside the admin panel of BigBear 2.0, an Evilginx2-based phishing-as-a-service operation run by someone known as 'General Boss'. The panel contained 5,137 records tied to 461 organizations: 1,032 plaintext passwords and 4,148 session cookies, with 474 complete MFA-bypassed authentications. The adversary-in-the-middle proxy captures Microsoft 365 session cookies that can be replayed to access email, Teams, SharePoint, and OneDrive, potentially pivoting into Entra ID and federated SaaS. The operation was still active, used custom JavaScript to disable FIDO2/WebAuthn on phishing pages, and routed logins through a residential proxy pool spanning 69 countries.

The Register · Security · 8d agoPhishing & fraud in the wild1

Critical N-able N-central Vulnerability and Active Exploitation

N-able N-central pre-auth RCE zero-day CVE-2026-86218 (CVSS 10.0) is exploited in the wild; on-prem admins must upgrade to 2026.3 HF4.

N-able disclosed a third N-central vulnerability, CVE-2026-86218, a pre-authentication RCE rated CVSS 10.0, and released hotfix 2026.3 HF4 superseding build 2026.3.1.13. Huntress reproduced an exploit chain involving an authentication bypass (CVE-2026-86206/CVE-2026-86207) after a fully patched customer's N-central production server was compromised on September 4. Attackers appended strings like .invalid to account names and probed the /remoteControlAction.do?method=getPierDetails endpoint; Huntress worked with Cloudflare to disable adversary tunnel infrastructure. Hosted N-central instances are already patched; on-prem administrators must upgrade immediately.

Huntress · 10d agoExploit / PoC in the wildCVE-2026-86218CVE-2026-86206CVE-2026-86207+2 CVEs

New Passkey Attacks Can Recover Synced Private Keys or Bypass Phishing

Three research teams showed passkey bypasses: WebAuthn assertion replay in Microsoft Entra ID, synced-passkey key recovery in Google Password Manager, and Windows Hello key reuse.

SpecterOps' Pass-the-Passkey research showed Windows stored past YubiKey signatures in cleartext and chained this with Microsoft Entra ID passkey validation weaknesses to impersonate privileged users despite phishing-resistant MFA; the Windows Event Logging Service issue is tracked as CVE-2026-34348 (CVSS 6.5) and fixed in July 2026 updates. Unit 42's Golden Pass-ta-key attack recovered the 32-byte Security Domain Secret protecting Google Password Manager synced passkeys from Chrome on Windows via pre-existing malware. Dirk-jan Mollema showed in-session malware can use a hardware-bound Windows Hello for Business key without a fresh PIN or biometric check. Microsoft applied Entra-side mitigations for the relay assertion issue; no real-world exploitation has been reported.

The Hacker News · Aug 11, 2026VulnerabilityCVE-2026-34348