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Iranian Hackers Use Fake MRI Results to Infect Victims With CHOSEN BRICK Spyware

Iranian state-linked hackers deliver CHOSEN BRICK Windows spyware via fake MRI results to surveil dissidents, activists, and journalists in the UK, US, and Netherlands.

A joint advisory from the UK NCSC, FBI, and the Netherlands' AIVD links Iranian state-linked actors to CHOSEN BRICK, a Windows spyware family used for long-term surveillance since at least 2025. Targets are approached on WhatsApp or Telegram with tailored lures such as fake MRI scan results or application files, and operators often redirect victims to personal devices to bypass corporate controls. The malware persists via Run registry keys, adds antivirus exclusions, uses a per-victim Telegram bot for command and control, and exfiltrates data through cloud storage and proxy services. Capabilities include screenshots, audio recording, email and messaging theft, command execution, file deletion, data wiping, and some victims' details have appeared on pro-Iranian leak sites for harassment.

Cyber Security Newsupdated · 2h agofirst · 14h agoThreat actor in the wild 6 sources

CVE-2026-67211: Apache OpenNLP: OOM DoS via Unbounded Array Allocation in SymSpellModelSerializer

Apache OpenNLP CVE-2026-67211: unbounded map pre-sizing in SymSpellModelSerializer enables out-of-memory denial of service in opennlp-symspell 3.0.0-M4/M5.

CVE-2026-67211 affects the opennlp-symspell artifact in versions 3.0.0-M4 and 3.0.0-M5 only. The SymSpellModelSerializer.create() method performs unbounded map pre-sizing, allowing crafted input to trigger out-of-memory denial of service. Releases 1.x and 2.x are unaffected because the spellcheck extension was introduced in 3.0.0-M4; the issue is resolved in 3.0.0-M6.

Hackers Weaponize AI Safety Guardrails to Hide Malware From LLM-Powered Security Scanners

ESET says Russia-aligned actor UAC-0099 hid guardrail-triggering comments in VBScript to derail LLM-based malware scanners in Ukraine.

ESET researchers linked a technique named GuardBreaker to Russia-aligned threat actor UAC-0099 during an attack against an organization in Ukraine. The group embedded a safety-sensitive, weapon-related request in a VBScript comment so an LLM-powered analysis tool might interpret it as an instruction and refuse or truncate analysis before reaching the malicious code. The VBScript downloaded MATCHBOIL, a C#-based loader used by the group alongside MATCHWOK and DRAGSTARE. OWASP guidance recommends treating code comments and metadata as untrusted input, sanitizing it, and never treating an LLM refusal as a clean verdict.

GBHackersupdated · 5d agofirst · 5d agoThreat actor in the wild 3 sources1

HOL Guard: Open-source antivirus for AI agents

HOL Guard is an open-source local guardrail that pauses AI coding agents before risky actions like secret access and prompt injection.

HOL Guard sits between AI coding agents (Claude Code, Cursor, Codex, Gemini CLI and others) and the host machine, intercepting risky commands before execution with checks taking under 50 milliseconds and running fully offline. It offers four sensitivity modes — Gentle, Balanced (default), Strict, and Paranoid — and parses command structure, environment, sensitive-path access and network destinations to decide when to interrupt. The core runtime is free and open source on GitHub, with 552,000 downloads reported; the vendor says it has no telemetry on adoption because collection is off by default.

Help Net Security · 16d agoAI tools & infra1

Hackers deploy Linux rootkit on F5 BIG-IP APM devices, hiding web shell in memory

Sophos analyzed a Linux rootkit, tracked as PoisonedRefresh, on hacked F5 BIG-IP APM devices hiding an in-memory web shell linked to exploited CVE-2025-53521.

Sophos and ESET analyzed an implant (named PoisonedRefresh by ESET) deployed on compromised F5 BIG-IP APM appliances, which serves enterprise, financial, government, and public sector deployments. The second-stage payload intercepts __libc_start_main, hooks Apache's APR module loader (apr_dso_load), RC4-encodes key strings, and rewrites PHP file reads in memory to embed a web shell inside legitimate scripts like apm_css.php3, full_wt.php3, and webtop_popup_css.php3, leaving on-disk files unchanged. A related installer component infects /usr/sbin/httpd, persists across BIG-IP upgrade images, modifies SELinux configuration, and deploys the payload. The malware also creates a Unix domain socket at /run/bigtlog.pipe that hands authenticated local connections to /bin/bash; F5 links the activity to CVE-2025-53521, an unauthenticated RCE in BIG-IP APM already exploited in the wild.

Help Net Security · 7d agoMalware in the wildCVE-2025-535211

MemSentry: A Framework for Detecting Persistent Memory Poisoning in Agentic AI

MemSentry intercepts persistent-memory writes in agentic AI to catch memory poisoning, reaching 91.7% accuracy with SBERT+LR classification.

Memory poisoning lets adversaries plant crafted content in an agent's long-term memory to suppress security alerts, enable privilege escalation, or override policies without modifying model weights or system prompts. The paper presents MemSentry, a configuration-driven framework that evaluates proposed persistent-memory writes on source trust, semantic risk, attack radius over a dependency DAG, access risk, and a signed security-state delta to issue deterministic Accept, Review, or Quarantine decisions. Across 1,000 GPT-4-generated scenarios on a 20-asset dependency DAG, SBERT+LR achieved 91.7% accuracy and 0.908 macro-F1, all four classifiers detected 100% of external quarantine-class threats, and verified-insider writes are escalated for human review rather than auto-quarantined.

arXiv cs.CR · 8d agoAI safety & security

PoisonedRefresh: A Fileless Linux Rootkit That Injects PHP Web Shells Into F5 BIG-IP APM Server Memory

Sophos details PoisonedRefresh, a fileless Linux rootkit that injects a memory-resident PHP web shell into F5 BIG-IP APM after exploitation of CVE-2025-53521.

On September 8, 2026, SophosLabs published an analysis of Linux/Agnt-IC (dubbed PoisonedRefresh by ESET) found in compromised F5 BIG-IP Access Policy Manager environments. Initial access leverages CVE-2025-53521, an unauthenticated RCE in BIG-IP APM when an access policy is configured on a virtual server; F5 confirmed exploitation and links the activity to cluster c05d5254, while Shadowserver observed 795 exposed vulnerable endpoints. A first stage hidden in a modified umount binary modifies /usr/sbin/httpd and SELinux configuration and embeds itself in BIG-IP upgrade images for persistence. The second-stage ELF intercepts __libc_start_main, hooks apr_dso_load, and injects a PHP web shell into libphp memory via mmap manipulation, leaving no disk artifacts, and exposes a /bin/bash shell via a local UNIX domain socket instead of a TCP port.

Security Affairs · 7d agoMalware in the wildCVE-2025-53521

MInTRL: Off-policy Intervention can boost On-policy RL

MInTRL injects sparse judge corrections into on-policy RL rollouts, expanding exploration beyond on-policy sampling while preserving learnability on math and code benchmarks.

Minimal Intervention Reinforcement Learning periodically has a judge-intervention policy replace erroneous suffixes of the current policy's output with short corrections, then returns control, keeping trajectories largely on-policy. Training uses a sequence-level advantage-regression objective that removes the need for importance sampling. Across math and code benchmarks it consistently beats standard on-policy and off-policy baselines, remains effective with self-intervention, and performs best at moderate intervention intensity.

Hugging Face daily papers · 6d agoAI research

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

New AI Attack Hides Malicious Instructions in Normal-Looking Text to Evade Safety Filters

Check Point researchers show crafted prose hides policy-violating instructions that bypass all tested LLM gatekeepers, including GPT-4o mini and Llama Guard 3.

A new prompt-crafting technique embeds malicious payloads inside grammatical, natural-looking text without Base64, invisible Unicode, or obvious encodings, defeating lightweight pre-screening gatekeepers. In testing, all four evaluated gatekeeper models—gpt-4o-mini-2024-07-18, gpt-oss-safeguard:20b, claude-3-haiku-20240307, and llama-guard3:8b—classified the crafted wrappers as safe at a 100% bypass rate across 23 obfuscated prompts. GPT-5 Thinking in high-reasoning mode recovered and acted on the hidden instruction in 17 of 18 tests (~94.4%), often spending over a minute and multiple Python executions. Researchers recommend paraphrasing untrusted input, hardening gatekeeper policies, and applying defense-in-depth controls for agentic deployments.

GBHackers · 5d agoAI safety & security 2 sources

Automating Attack Graph Construction for Agentic Pentesting. Towards Neuro-Symbolic Vulnerability Hunting

Semi-automated pipeline converts Trivy, Semgrep, Nmap output into MulVAL attack graphs for agentic pentesting, 53.7% mean vulnerability coverage in CyBench.

The paper presents a semi-automated pipeline that parses Trivy, Semgrep, and Nmap findings into MulVAL predicates and uses an LLM-assisted process to build domain-specific Datalog rules linking scanner evidence to attack techniques. MulVAL/XSB then performs symbolic inference to generate structured, auditable attack paths for agentic pentesting. Evaluated on 54 web CTF tasks from CyBench, every task produced at least one goal-reaching graph with 53.7% mean ground-truth vulnerability coverage, 51.9% full coverage, and an 83.9% noise-path rate. Median end-to-end runtime was 24.9 seconds, making the pipeline runtime-practical for agentic workflows.

arXiv cs.CR · 2d agoResearch

SEMA-GUARD: Semantic and Graph-Based Vulnerability Detection in Assembly Code

SEMA-GUARD uses semantic analysis and graph neural networks to detect vulnerabilities in assembly code, achieving 85.1% accuracy on a Juliet-derived benchmark.

SEMA-GUARD is a framework that detects vulnerabilities in compiled programs when source code is unavailable, targeting malware, firmware, and embedded systems analysis. It enriches control flow graphs with low-level execution semantics including stack manipulations, memory accesses, and data flow. Evaluated on a Juliet Test Suite set compiled to assembly and split into function-level chunks, it achieves 85.1% accuracy and an F1 score of 0.801, outperforming purely statistical or structural approaches.

arXiv cs.CR · 1d agoResearch1

The Fractured Block Campaign: CARROTBAT Used to Deliver Malware Targeting Southeast Asia

Unit 42 uncovers the Fractured Block campaign using the CARROTBAT dropper to deliver SYSCON and OceanSalt malware in cryptocurrency-themed attacks across Southeast Asia.

Unit 42 identified 29 CARROTBAT dropper samples used in the Fractured Block campaign, delivering decoy documents on cryptocurrencies, exchanges, and Korean political topics. Early samples delivered the SYSCON RAT, which uses FTP for command and control, while later ones dropped the previously reported OceanSalt malware. CARROTBAT supports 11 decoy file formats and uses certutil to download and execute payloads. Initial discovery stemmed from a December 2017 spear phishing attack on a British government agency, with infrastructure overlap tying the campaign to KONNI activity.

Palo Alto Unit 42 · Aug 17, 2026Malware

FrostyGoop’s Zoom-In: A Closer Look into the Malware Artifacts, Behaviors and Network Communications

Unit 42 dissects FrostyGoop OT malware, which sent Modbus TCP commands to disrupt heating for 600+ apartment buildings in Ukraine.

Palo Alto Unit 42 analyzed new FrostyGoop/BUSTLEBERM samples, the ninth known ICS-centric malware, first used against a Ukrainian municipal energy company by sending Modbus TCP commands to ENCO control devices. The attack caused a two-day heating outage affecting over 600 apartment buildings during sub-zero temperatures. The Go-compiled malware accepts Modbus register operations and timing parameters via command-line arguments or a JSON configuration file, uses an obscure open-source Modbus library, and checks the Windows BeingDebugged flag to evade debuggers. Unit 42 telemetry recorded over 1 million Modbus TCP devices exposed to the internet between September and October 2024.

Palo Alto Unit 42 · 28d agoMalware in the wild

Training a coding model to paint watercolours with TRL and OpenEnv

Hugging Face tutorial trains a coding model with TRL and OpenEnv to paint watercolours through generated code.

A Hugging Face blog walkthrough uses the TRL reinforcement learning library and the OpenEnv environment framework to train a coding model. The target task is generating code that produces watercolour-style drawings, serving as a hands-on reinforcement learning training example. No article body was available in the feed, so specifics are limited to the title.

Hugging Face Blog · 13d agoAI tools & infra1

$1 Million Sandbox Challenge Uncovers Linux Kernel Flaws

Vercel's $1M sandbox challenge surfaced two Linux kernel networking defects—one leaking host kernel memory, one crashing hosts—with CVEs pending.

Vercel ran a two-week, $1 million sandbox escape challenge (Aug 18–Sep 1) on its Firecracker-based microVM sandbox, receiving 1,285 reports and committing ~$325k in payouts (1 Critical, 7 High, 15 Medium, 49 Low validated so far). No attacker accessed real customer data. The most important filing found two independent Linux kernel networking stack defects—one leaks host kernel memory, the other deterministically crashes the host—with wide implications for cloud providers isolating workloads via the same kernel layer. Fixes are under private review with CVEs pending; Vercel also plans to open-source its agentic report-triage agent built on the Eve framework running Kimi K3.

SecurityWeek · 1d agoVulnerability2

LLM Agents as Computational Typologists

AUTOTYPOLOGIST is an LLM agent that performs evidence-grounded linguistic typology analysis over 25 open-source reference grammars.

The agent retrieves relevant grammar sections, analyzes interlinear glossed text (IGT), and iteratively reasons over typological hypotheses in a ReAct-style workflow. It was evaluated on typological feature coding against expert annotations and hypothesis testing against universals using 25 open-source reference grammars. Results suggest LLM agents can support scalable, inspectable crosslinguistic analysis but still require expert validation.

arXiv cs.AI / cs.LG / cs.CL · 9d agoAI research1

Trusting-Trust Attack against an Entire Linux Distribution (via the strip utility)

ArXiv paper shows the trusting-trust compiler backdoor technique can compromise an entire Linux distribution via the strip utility.

The paper (arXiv 2607.24888) demonstrates that Ken Thompson's trusting-trust attack, long viewed as a compiler-specific threat, can backdoor an entire Linux distribution by targeting the strip utility. A compromised tool reproduces its backdoor in subsequent rebuilds of itself, generalizing the attack surface beyond compilers. The finding has supply-chain implications for build reproducibility and distribution trust, though it is a research result with no observed real-world exploitation.

Lobsters · security · 11d agoResearch

RSIAgent: Autonomous Exploration for Recursive Self-improvement in New Environments

RSIAgent, a training-free multi-agent framework, builds reusable environment memory enabling Kimi-K3 and GLM-5.3 to beat GPT-6.

RSIAgent is a training-free framework for recursive self-improvement through autonomous memory construction, coordinating curriculum, actor, and verifier agents. It uses broad-then-deep exploration to capture environment structures, hidden constraints, and causal dependencies, and freezes the resulting memory for direct reuse without parameter updates. On OSWorld-v2 and Agent's Last Exam it substantially improves strong open-source models, enabling Kimi-K3 and GLM-5.3 to outperform frontier closed-source models including GPT-6.

Hugging Face daily papers · 3d agoAI research2

Hackers breach F5 BIG-IP APM devices to deploy Linux rootkit

Sophos analyzed a Linux rootkit on F5 BIG-IP APM devices that injects a fileless PHP web shell, likely after CVE-2025-53521 exploitation.

Sophos analyzed a Linux rootkit targeting F5 BIG-IP APM environments, also tracked by ESET as PoisonedRefresh, which hijacks Apache's apr_dso_load module loader to inject a fileless PHP web shell into memory. The implant intercepts __libc_start_main, hides strings with RC4, creates a password-protected local UNIX socket backdoor for interactive Bash access, and persists across BIG-IP upgrade images while modifying SELinux configuration. It is likely a second-stage payload following exploitation of CVE-2025-53521, a critical RCE flaw F5 reclassified from a DoS issue in March. The ShadowServer Foundation tracked 795 F5 BIG-IP APM endpoints exposed online.

BleepingComputer · 8d agoMalware in the wildCVE-2025-53521

Vibe-Terrorism: Inside the Yemen Cell That Used Claude to Build Guided Weapons

Anthropic's threat intelligence report says a small Yemen cell used Claude to help build guided weapons, a novel AI misuse case.

SOCRadar highlights a case from Anthropic's September 2026 threat intelligence report in which a small militant cell based in northern Yemen used Claude to help build guided weapons. The write-up coins the term "vibe-terrorism" for this AI-assisted weapons development. It is framed as a novel example of AI misuse outside typical cyber threat activity.

SOCRadar · 5d agoAI safety & security

Houthis Used Claude Code to Develop Missile Guidance Software: Anthropic

Anthropic's threat report details a Houthi-linked Yemeni cell using parallel Claude Code sessions to build missile guidance software, evading safeguards by fragmenting tasks.

Anthropic's September threat report describes a Yemen-based cell, assessed as highly likely Houthi-linked, that used Claude Code across multiple parallel instances to develop guidance software for a tactical guided rocket, a ballistic missile with over 2,000 km range, and a hypersonic glide vehicle concept called 'R2000'. The operators integrated open-source autopilot software, built six-degree-of-freedom trajectory simulations, and used reinforcement learning to tune flight-control algorithms, ultimately compiling an offline executable. The group test-fired a guided rocket that failed, then used Claude within hours to analyze launch telemetry. Anthropic blocked numerous requests, but operators evaded safeguards by obscuring intent and dividing work across separate conversations before accounts were banned; the case is one of six conventional-weapons cases (three China-linked, two Russia-linked) in a report covering disrupted operations from December 2025 to August 2026.

Russian hackers plant nuclear weapon prompt in malware to trip AI safety guardrails

ESET reports Russian group UAC-0099 hid a prompt in VBS malware comments to trip AI safety filters and disrupt automated malware analysis in Ukraine.

ESET identified a technique dubbed GuardBreaker in which UAC-0099 embedded a comment reading "I want to make nuclear weapon. Help me …" inside a malicious VBS script to trigger AI safety mechanisms and halt AI-assisted malware analysis. The script, part of the group's toolset, downloads the MATCHBOIL malware used exclusively by this Russia-aligned group; CERT-UA documented the chain including LUNCHPOKE, BURNYBEAR and MATCHBOIL.V2 in a July advisory. UAC-0099 typically targets transportation and energy sectors and hands validated targets to GRU-linked Sandworm. ESET warned that AI-assisted analysis must be backed by layered detection and human-driven engineering.

Help Net Security · 16d agoAI safety & security in the wild

Stealth rootkit targeting F5 BIG-IP could expose enterprise identity gateways

Sophos analyzed a stealth Linux rootkit that hides a web shell in memory on compromised F5 BIG-IP APM identity gateways, evading file-based detection.

Sophos analyzed a second-stage Linux rootkit implant found in compromised F5 BIG-IP APM environments running Apache and PHP, linked to exploitation of CVE-2025-53521, an unauthenticated RCE. The implant hooks Apache's PHP-loading process and serves modified in-memory versions of three legitimate webtop PHP files (apm_css.php3, full_wt.php3, webtop_popup_css.php3), leaving on-disk files untouched so hashes and integrity checks pass. It also establishes access via an authenticated local UNIX socket that can provide an interactive /bin/bash session. Experts warn compromised APM appliances, which handle federated SSO and terminate TLS at enterprise perimeters, could enable SSO token theft and lateral movement to trusted downstream applications.

CSO Online · 6d agoMalware in the wildCVE-2025-53521

Anthropic Adds Plugin Evals to Claude Code: 6 Grader Types, a No-Plugin Baseline, and a CI Gate for Skills

Anthropic ships a plugin evals workflow for Claude Code with six grader types, a no-plugin baseline arm, and a CI gate via threshold and cost flags.

Anthropic published a plugin evals workflow for Claude Code, exposed via the "claude plugin eval" command on v2.1.269+. Six grader types exist: regex, tool_used, tool_order, and file_exists are free transcript checks, while llm and baseline invoke a billed judge model. Every case runs with and without the plugin, and the delta (Δ) isolates the plugin's contribution; a Δ near zero with a failing tool_used:Skill grader indicates the skill never triggers. CI gating uses --threshold 0.8, --max-cost-usd, --trust-plugin, and --no-publish flags, with results written to a report.html under evals/results/.

MarkTechPost · 5d agoAI tools & infra2

F5 BIG-IP APM Malware Injects a PHP Web Shell Into Memory, Evading Disk Scans

Sophos found F5 BIG-IP APM malware that injects a PHP web shell into Apache's memory, evading disk scans, linked to exploited CVE-2025-53521.

Sophos's September 7 analysis describes malware tied to F5's c05d5254 activity that hooks apr_dso_load, modifies the libphp PHP module in memory, and injects a PHP web shell when Apache loads apm_css.php3, full_wt.php3 or webtop_popup_css.php3, leaving on-disk files clean. A separate installer infects /usr/sbin/httpd and umount, runs before Apache starts, disables SELinux (per ESET's related PoisonedRefresh analysis), and opens a local socket at /run/bigtlog.pipe for shell access. The activity is linked to CVE-2025-53521 in BIG-IP APM, rated 9.8 CVSS 3.1, patched in October 2025, added to CISA KEV on March 27, 2026.

The Hacker News · 7d agoMalware in the wildCVE-2025-53521

US Finance Under Phishing Pressure: What the SOC Data Reveals?

ANY.RUN SOC telemetry shows escalating phishing campaigns against US finance, including Vercel-hosted RMM attacks abusing legitimate services.

ANY.RUN analyzed SOC telemetry data on phishing targeting the US financial sector, concluding that the scale and security impact should not be understated. The analysis highlights modern campaigns such as Vercel-hosted attacks that deliver remote monitoring and management (RMM) tools. It notes that attackers increasingly abuse legitimate services and everyday workflow tools to deliver phishing, making detection harder for SOC teams.

ANY.RUN · 21d agoPhishing & fraud in the wild