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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 accounts at users’ expense

Malwarebytes reports infostealers are stealing Claude session cookies to hijack Anthropic accounts and consume victims' usage at their expense.

Anthropic warned that infostealer malware operators are harvesting Claude session cookies from infected machines. Attackers replay the stolen cookies to take over users' accounts and consume their usage quotas, affecting the victims' own access. The activity involves observed account hijacking rather than a flaw in Claude itself.

Malwarebytes Labs · 15d agoMalware in the wild

JSCeal Malware Can Bypass Google Authentication Using Stolen Session Cookies

Check Point details JSCeal, a V8-compiled JavaScript stealer that replays stolen cookies to bypass Google authentication, spread via crypto malvertising.

Check Point Research's new report analyzes JSCeal, a compiled V8 JavaScript malware obfuscated with javascript-obfuscator using RC4-protected strings, control-flow flattening, and proxy functions. Delivered through fake TradingView installers on malvertising sites overlapping the WEEVILPROXY/MeadowLocust and SourTrade campaigns, it harvests cookies, passwords and OAuth tokens from Chromium browsers, records keystrokes and screenshots, and can replay stolen Google session cookies to bypass authentication. It also installs a local proxy with service-specific handlers for Binance, Bybit, and Ledger to intercept and modify cryptocurrency-related traffic.

The Hacker News · 9d agoMalware in the wild1

'NovaCookies' Kit Steals Microsoft 365 Sessions for $320 a Month

New NovaCookies adversary-in-the-middle phishing kit lets low-skill actors steal Microsoft 365 session cookies for $320 per month.

Dark Reading reports on NovaCookies, an adversary-in-the-middle (AitM) phishing service sold for roughly $320 per month. The kit lowers the barrier to entry for attackers to run credential-harvesting attacks against Microsoft 365. It goes beyond credentials by stealing active session cookies, enabling account takeover without triggering MFA.

Dark Reading · 21d agoPhishing & fraud

Chrome adopts what may be the best protection yet against account takeovers

Chrome adopts device-bound session credentials that tie login sessions to a specific device, defending against cookie-theft account takeover attacks.

Chrome is adopting device-bound session credentials, which bind authenticated sessions to the physical device rather than to transferable cookies. The mechanism targets a common account takeover technique in which attackers steal session cookies and replay them on other machines. Ars Technica characterizes it as possibly the strongest protection yet against this class of takeover, which has become increasingly common.

Ars Technica · Security · Aug 11, 2026Tools

Hackers are stealing Claude tokens from subscribers

Infostealer malware is stealing Claude login sessions, letting attackers mint OAuth tokens and burn subscribers' paid usage largely undetected.

Anthropic confirmed a bad actor used common infostealer malware to steal Claude login sessions from users' computers and consume their paid usage. A UK consultant saw idle token usage climb, and Anthropic suspended his account, invalidated sessions and Claude Code tokens, and issued a £44.49 partial refund on his $200-per-month plan. Multiple other users on Reddit and GitHub reported similar theft; Anthropic signed out affected users and issued refunds, but still lacks itemized usage reporting to help users detect misuse.

TechCrunch · AI · 8d agoAI safety & security in the wild1

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

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

From Infostealer Log to Marketplace Listing: A Technical Walkthrough of the Credential Theft Pipeline

Cyble walkthrough maps how infostealer logs move from endpoint infection through aggregation and enrichment to dark web credential marketplace sales.

Cyble breaks the credential theft pipeline into stages: infostealer execution harvesting browser credential stores, cookies, session tokens, crypto wallets, and FTP configurations; aggregation of stealer logs via C2 panels into bundled archives; parsing and enrichment against previously leaked datasets; and final listing on dark web marketplaces. Enrichment adds employer and role context that raises prices and enables credential stuffing across reused passwords. The report advises SOC teams to monitor stealer logs and marketplace chatter early rather than waiting for breach alerts.

Cyble · 6d agoMalware1

Anthropic Users Hit by Infostealer Attacks, Session Thefts

A threat actor used multiple infostealers to harvest session data and hijack Claude accounts belonging to an unknown number of users.

Dark Reading reports that a threat actor deployed a variety of infostealer families to collect session information, which was then used to access Claude accounts belonging to an unknown number of users. Anthropic has not disclosed the scale of the compromise. The incident underscores session token theft via infostealer logs as an effective route into AI platform accounts.

Dark Reading · 16d agoMalware in the wild

CaptiveCrunch: Midnight Blizzard Weaponizes Hotel Wi-Fi Captive Portals to Steal Microsoft 365 Credentials

Zscaler details CaptiveCrunch: Midnight Blizzard's Storm-2945 compromises hotel Wi-Fi captive portals to redirect guests and harvest Microsoft 365 credentials via device code phishing.

Zscaler ThreatLabz analyzed the CaptiveCrunch credential theft campaign first reported by Microsoft on July 31. Microsoft attributes the activity to Storm-2945, a sub-cluster of Russia-linked Midnight Blizzard (APT29, Cozy Bear, NOBELIUM, BlueBravo). The actor manipulates DNS and HTTP traffic on captive portal networks at hotels and conference centers, redirecting victims to attacker-controlled infrastructure for Microsoft 365 credential harvesting, device code phishing, and malware delivery. Evidence indicates shared captive portal services were compromised rather than each venue being breached individually.

Zscaler ThreatLabz · Aug 11, 2026Threat actor in the wild

IT help-desk vishing tricks executives into handing over Microsoft 365 access

Arctic Wolf tracks PREY-0058 (linked to UNC6671), a vishing campaign stealing Microsoft 365 session tokens via AiTM panels for SaaS data theft and extortion.

Arctic Wolf is tracking a campaign, PREY-0058, sharing tradecraft with Google Threat Intelligence Group's UNC6671, in which callers posing as internal IT talk employees through fake passkey/MFA setups. Operator-controlled adversary-in-the-middle pages harvest passwords and MFA approvals to seize session tokens, then actors enumerate and bulk-exfiltrate data from SharePoint, OneDrive, Exchange, and Box. Extortion brands include BlackFile, Pink, Helix, Cinder, and Redact; targets are mostly US-based executives in construction, healthcare, real estate, finance, and professional services, with exfiltration shifting to residential proxies like NodeMaven.

Help Net Security · 8d agoThreat actor 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

IT Help Desk Impersonation Lets Hackers Bypass MFA

Arctic Wolf tracks PREY-0058 posing as IT help desk to steal Microsoft 365 sessions via AiTM panels, then extorting executives after SaaS data theft.

Arctic Wolf documented a threat cluster tracked as PREY-0058 that impersonates internal IT help desk staff by phone, luring Directors, VPs, and executives to authentication-themed URLs formatted as victim-organization lure domains. Adversary-in-the-middle panels intercept credentials and MFA approvals, and stolen sessions are replayed through residential proxies such as NodeMaven from IPs matching the victim's geo-location and ASN, defeating impossible-travel alerts. Attackers perform discovery against SharePoint and Entra ID, then harvest data from OneDrive, Exchange, and Box before issuing extortion demands. Defenders are advised to require managed devices, use phishing-resistant MFA like FIDO2, enable Continuous Access Evaluation, and monitor sign-ins, SharePoint SearchQueryPerformed, and MailItemsAccessed events.

Security Affairs · 8d agoPhishing & fraud in the wild1

Malicious Twitch Extension Exposes OAuth Tokens of 30,000 Chrome and Firefox Users

Malicious 'Twitch Enhanced Viewer | JeetBot' browser extension stole live OAuth session tokens from roughly 31,000 Chrome and Firefox users.

Socket.dev found the cross-store extension 'Twitch Enhanced Viewer | JeetBot' rerouted Twitch playlist requests through operator-controlled proxies, attaching the victim's account-level OAuth token as a URL parameter where it could be logged in cleartext. About 30,000 Chrome and 552 Firefox installs were exposed, with tokens forwarded for nearly every watched channel to infrastructure tied to a Russian commercial bot service. The stolen bearer token enables chat, whisper, account-setting access and channel-point spending without the password or 2FA.

Cyber Security Newsupdated · 2d agofirst · 2d agoMalware in the wild 2 sources

Session Attestation for Unmodified TLS Services in Confidential Virtual Machines

SessionLatch adds session attestation to unmodified TLS services in confidential VMs, cutting short-upload latency 63.1% versus TNG on Hygon CSV.

SessionLatch provides session attestation for confidential virtual machines without modifying applications, TLS implementations, or certificates. It relies on trusted observation of the server's locally generated ephemeral public key combined with standard TLS key confirmation, moving attestation integration to the operating system via a temporary latch that overlaps evidence exchange with the TLS handshake. Implemented with Linux and Windows integrations and evaluated on real Hygon CSV attestation, it reduces short-upload mean latency by 63.1%/23.0% relative to TNG in interleaved Linux/Windows experiments, while preserving enterprise service authentication and the native TLS data path, and supports mutual attestation.

arXiv cs.CR · 7d agoResearch

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

NovaCookies Campaigns Abuse Genuine Docusign Notifications to Steal Microsoft 365 Sessions

NovaCookies AitM phishing kit, a Sneaky 2FA variant, uses genuine Docusign lures to steal Microsoft 365 sessions at hundreds of organizations.

Island disclosed NovaCookies, a $320/month adversary-in-the-middle phishing-as-a-service platform that relays Microsoft 365 sign-ins through attacker infrastructure to capture credentials, MFA codes, and authenticated sessions. Campaigns abuse genuine Docusign envelopes and Microsoft/Google redirect hops so each step looks legitimate, with lure domains on .vu and alternating-case labels such as PwPt-sHaRe. Proofpoint assesses NovaCookies as a Sneaky 2FA variant with added flows for Okta and Entra domains federated to GoDaddy, and a fully managed PhaaS model. It has targeted hundreds of organizations in the U.S., U.K., Canada, Germany, Israel, and the U.A.E., and is advertised via Telegram with anti-analysis checks like a Cloudflare gate.

The Hacker News · 15d agoPhishing & fraud

Attackers Exploit PaperCut Flaws to Steal Credentials From Schools and Universities

Attackers exploit newly disclosed PaperCut auth bypass CVE-2026-81578 and RCE CVE-2026-82078 to steal credentials from schools and universities in the US and Europe.

Arctic Wolf observed threat actors chaining CVE-2026-81578 (authentication bypass) and CVE-2026-82078 (remote code execution) in PaperCut to execute commands, perform reconnaissance, and create privileged accounts on servers at K-12 schools and universities in the US and Europe. Post-exploitation includes registry hive collection with lsa_collect.exe delivered via certutil, Meterpreter Java payloads from 194.180.48.134, and searches of PaperCut config files for passwords, LDAP bindings, and tokens. Stolen logins could provide a pathway into other critical systems across compromised environments.

The Hacker News · 11d agoExploit / PoC in the wildCVE-2026-81578CVE-2026-820781

Zero-Click Grok Chat History Theft: Adversa AI Demonstrates Cryptographic Context Injection

Adversa AI's Cryptographic Context Injection bypasses AI guardrails using AES-encrypted payloads, enabling zero-click theft of Grok users' full chat histories.

Adversa AI researcher Rony Utevsky disclosed Cryptographic Context Injection, which hides instructions in AES-256-GCM ciphertext and tricks models into decrypting them inside their own code execution runtime, where the output is treated as trusted. Demonstrated against xAI's Grok, it stole user names, locations, subscription tiers, and full chat histories with zero clicks, and against Google's Gemini to bypass safety rules, generate incendiary-device instructions, and expose system instructions. Reported to xAI on June 3, 2026, the Grok attack remained reproducible as of August 19, 2026; the Gemini issue was not formally reported because Google's bug bounty excludes jailbreaks.

Security Affairs · 24d agoAI safety & security

Credential Theft: How Attackers Steal & Use Stolen Credentials

Huntress explains how attackers steal credentials through phishing, AitM, infostealers, and dumping, then use them for lateral movement, BEC, and ransomware.

Huntress published an educational overview of credential theft, citing that roughly 70% of confirmed data breaches begin with stolen credentials. It details acquisition methods including phishing, adversary-in-the-middle attacks that capture MFA session tokens, infostealers (nearly a quarter of threats Huntress observed in 2025), Mimikatz-based credential dumping, credential stuffing, and password spraying. The piece then covers post-theft actions such as lateral movement, privilege escalation, account takeover, business email compromise, and ransomware, and closes with behavioral detection guidance and layered prevention strategies.

Huntress · 6d agoResearch

Mapping out your unknown: A threat hunter’s guide to GitHub

Datadog Security Labs publishes a threat-hunting guide with audit-log queries to detect GitHub token theft, device code phishing, and source code exfiltration.

Datadog's threat-hunting guide covers GitHub audit log queries for detecting compromised accounts, stolen personal access tokens, and malicious OAuth app authorizations. Attackers typically obtain credentials through phishing, credential stuffing, leaked secrets, or device code phishing, then map private repositories, exfiltrate source code, and pivot into connected cloud and CI/CD environments. The guide maps detections to MITRE techniques like T1078 and T1528 and documents GitHub logging quirks affecting attribution, token metadata, and visibility fields.

Datadog Security Labs · 21h agoResearch in the wild1

Three Ukrainians to face charges for alleged hack of 610,000 Roblox accounts

Ukrainian prosecutors charged three men for stealing session tokens from over 610,000 Roblox accounts and selling them for an estimated $480,000.

Prosecutors in Ukraine's Lviv region said a 19-year-old organizer from Drohobych and two 22-year-old associates operated from May 2025 to April 2026, harvesting Roblox session tokens via infostealer malware disguised as game cheats and bonus software. They used software to validate stolen cookies and inventory virtual currency and rare items, then sold accounts via Russian platforms for as little as $0.80 each, advertising through Telegram channels and receiving crypto payments. All three are in custody facing charges of theft, money laundering, unauthorized computer interference, and illegal sale of restricted information, carrying up to 12 years in prison.

The Record · 7h agoPolicy & legal in the wild

Berlin investigates new data leak after hackers publish stolen login credentials

Berlin investigates a fresh leak after Rhysida hackers published stolen login credentials; the city refuses to pay the ransom demand.

Berlin confirmed hackers published additional stolen data, including login credentials, from a mid-August cyberattack on two city ministries responsible for urban development/housing and transport/climate. The Rhysida ransomware group claimed the breach in late August, saying it stole 5.79 TB of data including contracts, emails, passwords and classified information; Berlin acknowledged an extortion demand but refused to pay. Berlin's data protection regulator said the leak includes personal data on public employees and possibly residents, such as names, addresses, dates of birth and bank information. Germany's BSI separately linked the campaign to the TerminalFix fake-CAPTCHA technique and the LoremIpsumLoader/AxolotLoader malware tied to financially motivated Rhysida-associated hackers, days before Berlin's Sept. 20 election.

The Record · 9d agoRansomware in the wild1

Telegram Desktop XSS Vulnerability Lets Attackers Steal Entire Chat Histories

Stored XSS in Telegram Desktop HTML chat exports (CVSS 8.2) could let attacker-controlled inline keyboard buttons steal full chat histories.

ExPatch researchers Denis and Aleksander Rostilov found a stored XSS in Telegram Desktop's HTML chat export pipeline affecting builds before Beta 6.9.4 and Stable 7.0.1. Unsanitized inline keyboard button text becomes executable JavaScript when a user exports a chat and opens the HTML file in a browser, exposing messages, metadata, and local file paths, and enabling phishing overlays. Telegram patched the issue in commit 8457d13a during July 2026; no CVE had been assigned at disclosure time.

GBHackers · 1d agoVulnerability

Microsoft Tracks MacSync Stealer by Its Behavior, Not Its Domains

Microsoft correlates over 30 rotating domains to track MacSync Stealer, which steals passwords, SSH keys, wallets and AWS credentials.

Microsoft Defender Experts tracked MacSync Stealer, a macOS information stealer, by analyzing recurring behaviors rather than individual domains, linking over 30 domains to the campaign. The infection chain uses the ClickFix social engineering technique, tricking victims into pasting commands in Terminal, then uses curl, AppleScript, and native macOS tools to deploy the payload. The stealer targets Keychain data, browser passwords and cookies, SSH keys, AWS credentials, Kubernetes configurations, and Ledger and Trezor wallet data, staging data before exfiltration via chunked HTTP PUT requests. RST Cloud identified rapid C2 infrastructure replacement after initial public disclosure.

Security Affairs · 28d agoMalware

Hackers Use Fake Claude and ChatGPT Installers to Infect Mac Users With Password-Stealing Malware

Attackers distribute MacSync macOS infostealer via fake Claude and ChatGPT installers and sponsored search ads, stealing passwords, cookies, keys, and wallets.

SEQRITE reports a malware-as-a-service campaign pushing MacSync, a macOS password stealer, through sponsored search results and fake Claude and ChatGPT download pages. ClickFix-style prompts trick users into pasting a Terminal command that launches a stager, which loads an in-memory AppleScript to harvest credentials. The malware collects browser vaults, Keychain data, SSH keys, session cookies, messaging sessions, and cryptocurrency wallets, then persists via renamed LaunchAgents and can request screen-recording permissions.

Cyber Security News · 6d agoMalware in the wild 2 sources

Stealing AI Reasoning Traces

Researchers demonstrate a decryption jailbreak that extracts encrypted reasoning traces from Anthropic, OpenAI, and Google LLM APIs via weaker sibling models.

The paper exploits the fact that encrypted chain-of-thought blocks returned by LLM providers are interchangeable across sessions, users, and models within a provider's ecosystem. Injecting an encrypted trace into a weaker, less-safeguarded model from the same provider forces it to output the trace in plaintext, bypassing anti-distillation mechanisms. Decoding 315,320 reasoning blocks scraped from public repositories recovered 367 PII artifacts and 182 credentials, showing large-scale private data leakage. The flaw also enables hidden hazardous information disclosure and invisible prompt injections embedded in encrypted blocks; mitigations were proposed after responsible disclosure.

Schneier on Security · 8d agoAI safety & security

Honeypot-Omaha and batch.py [Guest Diary], (Wed, Sep 2nd)

A SANS ISC guest diary describes batch.py, a Python tool that consolidates honeypot logs and enriches IOCs with threat intelligence data.

Written by a SANS.edu BACS intern, the diary explains analysis of the DShield Honeypot-Omaha sensor, which uses Cowrie to emulate SSH and Telnet and log attacker activity. The author's batch.py script implements a four-phase pipeline with SHA-256-generated master and guest authentication to consolidate JSON and log files, correlate data via external APIs, and produce MITRE, CVE, geolocation, threat-score and fingerprint enrichment for investigated indicators.

SANS Internet Storm Center · 13d agoTools1