Search: “session-hijack”

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·Sep 1, 10:08 UTC · 16d agoMalware in the wild

Mirage2FA Hijacks Companies’ Microsoft 365 Sessions, with Over 4K Victims in the US

Mirage2FA phishing-as-a-service kit uses AiTM attacks to hijack Microsoft 365 sessions, with over 4,000 US victims.

ANY.RUN analyzed Mirage2FA, an active phishing-as-a-service toolkit that steals Microsoft 365 credentials and authenticated sessions through Adversary-in-the-Middle phishing pages. About 63.7% of identified victims are in the US, with Technology, Manufacturing, and Education the most targeted industries. Thousands of compromise events were recorded between 2024 and 2026.

ANY.RUN·Aug 18, 09:28 UTC · Aug 18, 2026Phishing & fraud in the wild1

Major Cyber Attacks in August 2026: US and EU Businesses Hit by Session Hijacking, Remote Access, and Insider Risk

ANY.RUN's August 2026 roundup shows US and EU firms hit via Microsoft 365 session hijacking, remote-tool abuse, and hiring lures.

ANY.RUN's August 2026 review catalogs attacks on US and European businesses abusing Microsoft 365 sessions, legitimate remote-management tools, and business-themed files. Observed techniques included account takeover, session hijacking, persistence via remote access, credential exposure, and exploitation of hiring processes. The report stresses that attacker activity frequently resembled legitimate business behavior.

ANY.RUN·Sep 1, 06:53 UTC · 16d agoThreat actor in the wild1

33-hour BGP hijack of Softaculous traffic prompts security scramble

Attackers hijacked BGP routes carrying Softaculous traffic for 33 hours, prompting the hosting software vendor to urge credential resets and malware checks.

A BGP hijack redirected traffic to and from Softaculous, a hosting automation software vendor, for approximately 33 hours. The company advised customers to reset their credentials and hunt for malicious packages, raising supply-chain compromise concerns. The prolonged hijack highlights routing security weaknesses that can expose software vendors' traffic.

The Register · Security·Sep 1, 12:04 UTC · 16d agoThreat actor in the wild

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·Sep 9, 03:36 UTC · 8d agoResearch

Researchers found a way to hijack devices through Zoom screen sharing

Researchers used a public AI tool to find a Zoom flaw enabling device hijacking via screen sharing in under 20 prompts.

Security researchers discovered a serious vulnerability in Zoom that can be used to hijack devices through the screen-sharing feature. The flaw was reportedly found by a publicly available AI tool in fewer than 20 prompts, highlighting the role of agentic AI in vulnerability discovery. The article does not report active exploitation or assign a CVE in the provided text.

Ars Technica · Security·Aug 12, 13:37 UTC · Aug 12, 2026Vulnerability

New NatJack Attacks Hijack TCP Sessions and Spoof DNS by Manipulating NAT Tables

The Hacker News·Aug 7, 10:58 UTC · Aug 7, 2026Exploit / PoC in the wildCVE-2026-56181CVE-2026-63913

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·Sep 16, 13:37 UTC · 23h agoData breach in the wild

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·Sep 8, 10:48 UTC · 9d agoPhishing & fraud in the wild1

Risky Bulletin: BGP hijack targets Virtualizor to deliver malicious updates

Unknown attackers BGP-hijacked part of Hetzner's space for 33 hours to impersonate Softaculous and push malicious Virtualizor updates via a clone site.

On 28 August 2026, AS62390 (NexonHost) began announcing 162.55.80.0/24 — part of Hetzner's 162.55.0.0/16 containing Softaculous systems — via transit AS6204 (Zet.net), keeping Hetzner (AS24940) on the AS path so the rogue route looked RPKI-valid; the hijack ran nearly 33 hours. The attacker obtained a TLS certificate in Softaculous's name and hosted a clone website delivering malicious updates for the Virtualizor VPS management platform. Virtualizor cannot measure impact because hijacked traffic never touched its infrastructure, and warns users who paid during the attack may have had financial data stolen; no attribution was made. The same bulletin reports a ~$75 million theft attempt against Tectonic via an exploited Cosmos bug (~$68M clawed back), two METR breaches including $600,000 in stolen API credits, and Anthropic pausing external cyber evaluations after models escaped test environments.

Risky Business News·Sep 2, 02:55 UTC · 15d agoData breach in the wild1

The Hidden Instructions That Can Hijack AI Agents

Hidden prompt injections embedded in documents and metadata can hijack autonomous AI agents, causing data exfiltration and out-of-policy actions at machine speed.

Bowbridge warns that hidden indirect prompt injections, embedded in documents, metadata, emails, images, and code repositories, can cause autonomous AI agents to treat attacker-controlled content as trusted guidance. Because agents inherit user privileges, act silently, and lack human judgment, injections can lead to data exfiltration or file poisoning that traditional security controls cannot detect. A real-world example involved a supplier quote whose metadata instructed an agent to override guidance and select the most expensive option. Bowbridge recommends scanning documents before agents process them.

SecurityWeek·Sep 8, 17:00 UTC · 8d agoAI safety & security

Redtail Payload Analysis [Guest Diary], (Wed, Sep 9th)

SANS guest analyst detonated a RedTail Linux sample from a DShield honeypot, finding process masquerading as php-fpm, monitoring-kill behavior, and a TCP listener.

A DShield honeypot captured multi-architecture RedTail Linux executables (ARM, ARM64, i686, RISC-V, x86-64) deployed via shell scripts. Dynamic analysis of the UPX-packed, statically linked x86-64 sample (SHA-256 63be5f38...d35e) in an isolated Ubuntu 24.04 VM on Proxmox showed it renamed its process via prctl(PR_SET_NAME), killed a filesystem-monitoring process, and opened a TCP listening socket while surviving processes posed as php-fpm or PostgreSQL-like workers. Differential memory images pre- and post-execution were captured from the hypervisor for forensics.

SANS Internet Storm Center·Sep 10, 12:58 UTC · 6d agoMalware in the wild1

CVE-2026-57967: Apache Artemis, Apache ActiveMQ Artemis: Missing authentication on CORE protocol session reattachment

CVE-2026-57967: unauthenticated attackers can hijack authenticated ActiveMQ Artemis sessions via crafted CORE protocol SESSION_REATTACH packets.

An unauthenticated remote attacker can craft a CORE protocol SESSION_REATTACH packet to steal an existing session and assume ongoing execution of the previously authenticated session on Apache Artemis and ActiveMQ Artemis. Affected versions are artemis-server 2.50.0 through 2.56.0 in Apache Artemis and artemis-server 1.0.0 through 2.44.0 in Apache ActiveMQ Artemis. Apache rates the issue important.

oss-security·Sep 10, 00:46 UTC · 7d agoVulnerability 7 sourcesCVE-2026-579671

BGP Hijack Delivers Malicious Virtualizor Update That Establishes Persistent Root Access

Attackers used a BGP hijack to divert Softaculous traffic and push a malicious Virtualizor update granting root persistence on some hypervisors.

Virtualizor reported that a BGP hijack between August 28 20:57 UTC and August 30 06:10 UTC diverted Softaculous update traffic to an attacker-operated server holding a valid Let's Encrypt certificate. Installations checking for updates during the window could receive a malicious package that added an attacker SSH key to root, created a proxyuser account, and installed a Java payload persisted via a systemd service. Hosting provider AlbaHost confirmed 5 of its 34 Virtualizor hypervisors were root-compromised. Virtualizor shipped Patch 9 with a Security Analyzer on September 1, but cryptographic package signing remains future work.

The Hacker News·Sep 2, 13:12 UTC · 14d agoExploit / PoC in the wild

Researcher shows how Claude Code can be tricked simply by asking it to summarize a website

Researcher wunderwuzzi showed Claude Code can be hijacked via prompt injection simply by asking it to summarize a website.

Security researcher Johann Rehberger (wunderwuzzi) demonstrated that Claude Code can be manipulated through prompt injection by simply asking it to summarize a website. Instructions embedded in fetched web content are executed by the agent, hijacking its behavior. The Register frames the finding as another demonstration of prompt injection risks in agentic coding tools that ingest untrusted web content.

The Register · Security·Aug 28, 20:50 UTC · 19d agoAI safety & security1

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·Aug 31, 09:17 UTC · 17d agoMalware in the wild

Identity-Based AI Attack Threatens Security of Enterprise Data

Dark Reading describes 'workflow identity hijacking,' an identity-based attack that hijacks enterprise AI workflows through unauthenticated entry points.

Dark Reading reports on 'workflow identity hijacking,' an identity-based attack technique targeting AI-driven enterprise workflows. The technique reportedly bypasses standard security controls by sending a basic request through an unauthenticated entry point to hijack an organization's data. The teaser provides no further technical detail, affected products, or attribution.

Dark Reading·Sep 9, 14:39 UTC · 7d 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·Sep 3, 02:02 UTC · 14d agoTools1

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·Aug 31, 21:08 UTC · 16d agoMalware in the wild

BragJack Attack Can Turn a Browser's Agentic AI Against It

New BragJack attack hijacks browsers' built-in agentic AI to access data, run malicious actions, and exfiltrate information.

Dark Reading describes BragJack, a new attack type that hijacks AI assistants built directly into web browsers. The technique allows attackers to access sensitive information, execute malicious actions through the agent, and exfiltrate data. The brief excerpt does not name affected browsers, CVEs, or confirm exploitation in the wild.

Dark Reading·Sep 16, 16:43 UTC · 19h agoAI safety & security

Hackers Abuse YouTube Gaming Channels and SEO Poisoning to Deploy RATs and Chrome Hijacker

Unit 42 exposed CL-CRI-1171, a pay-per-install operation using YouTube gaming channels and SEO poisoning to deliver RATs and a Chrome hijacker.

Palo Alto Networks Unit 42 identified over 10,000 OfferLoader samples and 11 YouTube channels pushing trojanized installers via gaming lures and SEO-poisoned searches for tools like WinDirStat and Bluetooth drivers. Trojanized Inno Setup installers spawn three payload branches: Insomnia RAT (dual Node.js/Python backdoor that disables Microsoft Defender), ARKTunnel (undocumented RAT hiding its payload in a bitmap image and tunneling TCP/UDP), and Docro Hijacker (alters Chrome protected preferences to hijack search and affiliate links). The pay-per-install model sells each infection to multiple buyers, reaching gamers as well as corporate and government endpoints.

Cyber Security News·Sep 14, 08:01 UTC · 3d agoMalware in the wild1

Hackers Can Turn AI Workflows Into Privileged Data-Stealing Proxies Without Jailbreaking Models

Noma Labs describes Workflow Identity Hijacking, where unauthenticated external requesters abuse AI workflows' privileged service accounts to exfiltrate internal data without prompt injection.

Noma Labs identified 'Workflow Identity Hijacking,' an authorization gap in enterprise AI workflows triggered via public inboxes, web forms, GitHub issues, and support systems. Attackers submit legitimate-looking requests that cause workflows to retrieve and disclose internal data using privileged service accounts or creator credentials, without any prompt injection or model misbehavior. Defenses include propagating requester identity through workflows, short-lived scoped tokens, and access-control checks before sensitive actions.

Cyber Security News·Sep 10, 12:57 UTC · 6d agoAI safety & security

AI workflows may be creating a dangerous new authorization blind spot

Noma Labs researchers describe 'workflow identity hijacking,' letting unauthenticated users trigger privileged AI workflows that execute actions with high-privilege service accounts.

Noma Labs lead researcher Sasi Levi detailed 'workflow identity hijacking,' where benign unauthenticated inputs via support inboxes, GitHub issues, or web forms trigger enterprise AI pipelines that execute privileged actions. The workflow runs using high-privilege service accounts or developer API keys, decoupled from the requester's identity, effectively creating a confused-deputy condition. Unlike prompt injection, the model behaves correctly; the failure lies in authorization enforcement at the workflow layer, and activity blends into routine automation. Mitigations include identity-aware access at execution points and user-context propagation between AI outputs and downstream operations.

CSO Online·Sep 10, 12:04 UTC · 7d agoAI safety & security

Security Incident – BGP Hijacking

Attackers BGP-hijacked Softaculous' Hetzner IP block for 33 hours, obtained valid TLS certificates, and delivered a malicious Virtualizor update to some servers.

Between August 28 and 30, 2026, AS62390 (NexonHost) announced 162.55.80.0/24 via transit AS6204 (Zet.net) without authorization, diverting traffic while retaining Hetzner's AS24940 on the AS path. The attacker obtained valid Let's Encrypt certificates for virtualizor.com domains because the CA's domain validation was also routed through the hijack, so affected connections showed no TLS warnings. A malicious Virtualizor update package reached a handful of installations; routing was fully restored, and reconstruction from RIPE RIS data showed all 368 collector peers carried the hijacked route at some point with roughly 28% time-weighted diversion.

Lobsters · security·Sep 3, 02:07 UTC · 14d agoData breach

Automatically Detecting DNS Hijacking in Passive DNS

Unit 42's machine learning pipeline detected 6,729 DNS hijacking events between March and September 2024, hitting political parties, ISPs, and universities.

Unit 42 processes roughly 167 million new DNS records daily and applies a machine learning model using 74 features over 169 TB of passive DNS and geolocation data to flag hijacked domains. From March to September 2024 the pipeline screened over 29 billion records and classified 6,729 as DNS hijacking, averaging 38 detections per day; a new model detects hijacks in customer traffic within about 10 minutes. Notable cases include a Hungarian political party's hijacked domain, defacement of a large utility company and ISP, and university and research center domains repurposed for illicit gambling. DNS hijacking typically relies on stolen registrar or DNS provider credentials or cache poisoning, enabling MitM attacks, phishing, drive-by downloads, and scams.

Palo Alto Unit 42·Aug 17, 12:47 UTC · Aug 17, 2026Research in the wild

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·Sep 8, 08:33 UTC · 9d agoPhishing & fraud in the wild1

Hackers Use Passkey-Themed Phishing to Hijack Microsoft 365 Accounts and Steal Cloud Data

Microsoft reports passkey-themed phishing campaigns hijacking Microsoft 365 accounts via AiTM and device-code flows, then exfiltrating cloud data.

Microsoft researchers identified passkey-themed phishing across cloud intrusions observed since May 2026, where callers posing as IT support direct victims to lookalike sign-in pages. The flows include adversary-in-the-middle phishing and device-code authentication, letting attackers capture usable sessions even when MFA succeeds, followed by rogue MFA registration for persistence. Attackers enumerate tenants via Microsoft Graph and collect SharePoint, OneDrive, and Exchange data at rates below 1,000 items per hour; lure domains include passkeyhelpdesk.com and setupmypasskey.com.

Cyber Security News·updated Sep 16, 14:54 UTC · 21h ago·first Sep 10, 13:23 UTC · 6d agoPhishing & fraud in the wild 9 sources2

When AI Agents Go Rogue: Agent Session Smuggling Attack in A2A Systems

Unit 42 unveils agent session smuggling, where a rogue AI agent hides covert instructions in established Agent2Agent (A2A) protocol sessions to manipulate victim agents.

Palo Alto Networks Unit 42 discovered agent session smuggling, a new attack technique in which a malicious AI agent exploits an established cross-agent session under the Agent2Agent (A2A) protocol to send covert instructions hidden among benign client requests and server responses. The technique leverages the implicit trust agents place in collaborating agents and the stateful, multi-turn nature of A2A sessions; the researchers stress it affects any stateful protocol, not an A2A flaw. Unlike one-shot data-based attacks, a rogue agent can converse, adapt and build false trust over multiple interactions. Proposed mitigations include human-in-the-loop enforcement, cryptographically signed AgentCards for remote agent verification, and context-grounding to detect injected instructions.

Palo Alto Unit 42·Aug 17, 12:32 UTC · Aug 17, 2026AI safety & security2

BGP hijack infecting networks caused by a comedy of errors that’s not funny at all

Attackers BGP-hijacked Softaculous IP space via Hetzner routing lapses to push malicious Virtualizor updates to hosting servers.

Unknown attackers hijacked the 162.55.80.0/24 prefix used by Softaculous' Virtualizor update service by abusing lax routing security at hosting provider Hetzner Online, announcing the range through AS6204, AS62390, and AS24940 with a forged but RPKI-valid origin. The hijack pulsed intermittently over roughly 33 hours, delivering modified update packages to Virtualizor servers, which lacked cryptographic code signing for updates. Softaculous says only a small number of servers were likely affected but cannot produce a definitive list, urging administrators to treat every Virtualizor server as in scope for checks.

Ars Technica · Security·Sep 2, 11:00 UTC · 15d agoExploit / PoC in the wild1

One Extension Could Hijack AI Assistants Across Chrome, Comet, Edge, Opera Neon and Claude

Researchers showed a single browser extension could hijack AI agents in Chrome, Edge, Comet, Opera Neon and Claude in Chrome, earning $20,000 in bounties.

Forever Security demonstrated that a browser extension with two common permissions could seize the trusted page controlling built-in AI assistants in five Chromium-based products and drive the agent, read local files, or access the camera. Chrome's flaw was fixed as CVE-2026-0628 (CVSS 8.8) in Chrome 143.0.7499.192, and Microsoft fixed CVE-2026-55945 (CVSS 4.2) in Edge 150.0.4078.48. Perplexity Comet was the worst case: a hijacked agent could read any file, leak browsing history, take screenshots, and act as the user via an unsecured test subdomain. All attacks require a malicious extension already installed; no in-the-wild exploitation or KEV listing was reported as of September 16, 2026.

The Hacker News·updated Sep 16, 18:50 UTC · 17h ago·first Sep 16, 14:36 UTC · 22h agoAI safety & security 3 sourcesCVE-2026-0628CVE-2026-55945