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GuardBreaker: Derailing AI-assisted malware analysis with a code comment

ESET names 'GuardBreaker': UAC-0099 embeds a nuclear-weapon question in VBScript comments to trip LLM scanner guardrails during analysis of its MATCHBOIL loader.

ESET researchers observed the Russia-aligned group UAC-0099 inserting a decoy prompt injection into a VBScript used to install its MATCHBOIL loader in an attack against a Ukrainian target, aiming to make LLM-based code scanners refuse and stop inspecting the file. The comment triggers safety guardrails with a request about building a nuclear weapons but has no runtime effect. Similar LLM-thwarting tricks have appeared in malicious PyPI and npm packages reported by Socket and StepSecurity. ESET recommends multi-model cross-validation of AI-assisted analysis and treating missing LLM output as requiring further checks.

ESET WeLiveSecurityupdated · 5d agofirst · 6d agoAI safety & security 3 sources1

Unit 42 Incident Response Archives

Palo Alto Networks Unit 42 markets its paid incident response services backed by threat intelligence and methodology from thousands of investigations.

This is a vendor product page describing Unit 42's incident response offering rather than a news article. It emphasizes containing, remediating and eradicating attacks using threat intelligence and a methodology developed from real-world incident casework. No new incident, vulnerability, or actor activity is reported.

Palo Alto Unit 42 · 8d agoIndustry 6 sources

Cybersecurity attention fades within months after a breach

ManageEngine survey of 700 breached organizations finds security attention fades within one to six months, while 91% still trust their posture.

A ManageEngine survey of 700 IT and security leaders in the US and Canada, all of whom had experienced a breach, found that 91% trust their current security posture and only 8% make security a permanent priority after an incident. 80% said post-breach focus lasts just one to six months, and nearly half made no wider changes after their incident. About two in three organizations using AI in security said they act on AI recommendations without additional verification. The report also flagged unclear ownership across security, IT, and business teams as a cause of delayed remediation.

Help Net Security · 2d agoIndustry

Bad Likert Judge: A Novel Multi-Turn Technique to Jailbreak LLMs by Misusing Their Evaluation Capability

Unit 42 details the Bad Likert Judge multi-turn jailbreak that abuses LLMs' evaluation capability, raising attack success rates over 60% across six frontier models.

Palo Alto Networks Unit 42 describes the Bad Likert Judge technique, a multi-turn jailbreak that asks a target LLM to act as a Likert-scale judge scoring the harmfulness of example responses. The highest-rated example in each scale can carry harmful content, bypassing the model's internal guardrails. Testing across six state-of-the-art text-generation LLMs showed an average attack success rate increase of more than 60% versus plain attack prompts, with tested models anonymized. The technique targets edge cases rather than typical use, and the article positions the work as guidance for defenders on potential jailbreak risks.

Palo Alto Unit 42 · Aug 17, 2026AI safety & security

Learning Intrusion Response Strategies for OT Systems

Researchers model OT intrusion response as a POMDP and train PPO-based automated response strategies effective against MITRE attacks in an emulated OT system.

The paper formalizes automated intrusion response for OT systems as a partially observable Markov decision process, with partial observability modeled from traffic measurements. Learning-based solution methods built on PPO are developed and evaluated on an emulated OT system. The resulting response strategies proved effective against several types of MITRE attacks for the studied use case.

arXiv cs.CR · 7d agoResearch2

Cybersecurity IR Workshop: The workshop you shouldn’t miss

Microsoft's DART team promotes a 2-3 day Cybersecurity Incident Response Readiness Workshop that stress-tests IR plans against simulated attacks.

Microsoft's Detection and Response Team (DART), which delivers Defender Experts incident response and has supported organizations across 54 countries, is offering its Cybersecurity Incident Response Readiness Workshop. The scenario-driven engagement exercises detection, investigation, containment, and decision-making across identity, endpoint, cloud, and communications, ending with prioritized recommendations. It is available to Unified Enterprise agreement customers via their Customer Success Account Manager.

Microsoft Security Blog · 15d agoIndustry

ATF responds to 'major' cybersecurity incident after ransomware gang's claims

The ATF is responding to a major cybersecurity incident claimed by a ransomware gang, with the US Justice Department investigating the breach.

The US Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) acknowledged a 'major' cybersecurity incident after a ransomware gang claimed responsibility for an attack. The US Justice Department is investigating the breach. Available reporting provides limited technical detail, and the scope of data theft and operational impact remains unclear.

The Register · Security · 20d agoRansomware

Unit 42 - Latest Cyber Security Research

Unit 42 briefing warns frontier AI models compress exploit development timelines and highlights 2026 incident response report findings on AI-accelerated attacks.

Palo Alto Networks Unit 42 published a threat briefing and Global Incident Response Report arguing that frontier AI models enable threat actors to move from initial access to exfiltration in minutes rather than months. The report found attacks are 4x faster, 65% of initial access is driven by identity-based techniques, and 87% of attacks unfold across multiple surfaces. The briefing offers CISO guidance on prioritizing defenses against AI-accelerated, automated attacks.

Palo Alto Unit 42 · 28d agoAI safety & security

Batten the Hatches: Cybersecurity with Military Mariners

Interviews with 20 U.S. Navy and Coast Guard mariners reveal informal, safety-oriented shipboard cyber risk models that may delay attribution and containment.

The study conducts semi-structured interviews with 20 military mariners from U.S. Navy and Coast Guard vessels to understand how service members recognize and respond to cyber risk aboard ships. Unique consequences of compromising military systems identified include weapon takeover and purposeful geopolitical escalation. Cybersecurity is organizationally abstract on ships, so mariners build cyber risk models from informal experience rather than formal instruction. A safety-oriented incident-response model creates resilience but may delay cyber attribution and containment.

arXiv cs.CR · 5d agoResearch

Revolut’s paperwork breach shows why insurers are rethinking what counts as a ‘cyber attack’

Revolut handed customer data to an attacker using a spoofed government email, prompting insurers to rethink cyber attack coverage definitions.

Revolut disclosed customer data after receiving a request from what appeared to be a genuine government email address; no servers were breached and no malware was involved. The social engineering incident has become a test case for how cyber insurers define a 'cyber attack'. The report is by Matthew Sellers. It highlights a growing gap between technical intrusions and data-loss incidents caused by impersonation.

DataBreaches.net · 1d agoData breach

Perturbation Probing: A New Diagnostic for the Fragility of LLM Safety

Unit 42 research shows LLM safety refusals concentrate in a thin neural layer, motivating external, multi-layered AI security controls.

Palo Alto Networks Unit 42 introduces Perturbation Probing, a diagnostic technique for measuring the fragility of LLM safety mechanisms. The research finds that safety refusal behavior is localized within a thin neural layer, implying small perturbations can undermine built-in refusals. The authors argue this motivates external, multi-layered security defenses on top of model-internal safety training.

Palo Alto Unit 42 · 19d agoAI safety & security

Threat Assessment: Egregor Ransomware

Unit 42 assesses Egregor ransomware, a Sekhmet variant likely run by former Maze affiliates using Qakbot, IcedID, and Ursnif for initial access.

Since September 2020, Unit 42 observed Egregor ransomware attacks across the U.S., Europe, Asia-Pacific, and Latin America, coinciding with the Maze team's shutdown announcement. Egregor, a variant of the Sekhmet family, uses commodity malware such as Qakbot, IcedID, and Ursnif for initial access, followed by scripts that modify firewalls, enable RDP, and deploy Cobalt Strike for reconnaissance and exfiltration. A PowerShell script uninstalls the McAfee agent and downloads the Egregor DLL via BITS, executed with the -passegregor10 key. Victims face a three-day ransom deadline before exfiltrated data is published on the Egregor Hall of Shame leak site.

Palo Alto Unit 42 · Aug 17, 2026Ransomware in the wild

Approval Integrity and Recovery in LLM Answer Publication

Study measures approval integrity in Lightcap LLM answer publication, finding the 14B response-act checker accepts 291 of 302 unsupported answers.

The study evaluates exact-content binding, authorization freshness, and checkpoint recovery in Lightcap's publication enforcement using 3,600 assessments over 900 human-annotated RAGTruth responses from three Ministral models. The production 14B response-act checker accepts 291 of 302 unsupported answers versus 41 for a direct-grounding baseline, with supported-answer retention of 95.2% versus 66.9%. A stateful recheck-recovery policy increases exact-match error by 9.23 percentage points relative to initial checkpoints, and controlled evidence-fingerprint changes expose asymmetric freshness enforcement between publication and recovery. A separate BIPIA prompt-injection experiment records zero target insertions among 266 valid editor outputs.

arXiv cs.CR · 2d agoAI safety & security

The Model Proposes, the Code Disposes: A Pre-Registered Ablation of a Verifier-and-Acceptance Stage in an LLM-Orchestrated Offensive-Security Agent

Pre-registered ablation finds a model verifier stage in an LLM offensive-security agent suppresses findings; removing it eliminated suppression with precision tradeoff.

The paper evaluates a verifier-and-acceptance stage in an LLM-orchestrated offensive-security agent via a pre-registered 20-run confirmatory ablation and a 2x2 factorial study with 40 runs on vulnerable lab targets. Removing the stage eliminated pre-report suppression (median 2 vs 0 findings, p = 0.00003) but reduced model-blinded shipped precision (0.471 vs 0.353, p = 0.0087). Suppression was attributed to the model verifier rather than deterministic acceptance rules, and an instrumented canary recorded zero external contacts in all 60 runs. The full design retained 93.8% of model-adjudicated true candidates but failed its pre-registered non-inferiority floor of 0.90.

arXiv cs.CR · 2d agoResearch

When the prompt becomes the payload: A practical pen-testing guide for GenAI, LLM and RAG applications

CSO Online publishes a practical penetration-testing guide for GenAI, LLM, and RAG applications, covering prompt injection, retrieval poisoning, and tenant isolation testing.

The guide frames LLM applications as attack graphs spanning prompts, retrieval layers, vector stores, tools, identities, and downstream APIs, arguing that conventional web testing misses instruction-vs-data channel risks. It builds on OWASP prompt injection guidance (direct vs. indirect injection) and NIST's 2025 adversarial machine-learning taxonomy, noting that RAG and fine-tuning do not remove injection risk. Recommended practices include documenting trust transitions across components, using canaries and synthetic records to avoid test side effects, running multi-turn and obfuscated injection campaigns, and verifying chains from poisoned documents to observable state changes. It also details testing RAG pipelines via controlled document poisoning across metadata, OCR layers, and code comments, plus cross-tenant isolation checks on retrieved document IDs.

CSO Online · 7d agoAI safety & security1

Logistics Giant Ceva Suffers Data Breach Impacting European Clients

Ceva Logistics suffers a supply chain attack and data breach with a large blast radius impacting European clients.

Ceva Logistics, a major global logistics provider, suffered a data breach impacting its European clients. The incident appears to be a supply chain attack with a large potential blast radius affecting downstream customers. Details on compromised data volumes and the initial intrusion vector remain limited.

Infosecurity Magazine · Aug 11, 2026Data breach

CS-Guard: Benchmarking LLM Guardrails for Code Generation Security

CS-Guard benchmark shows LLM code-generation guardrails fail widely, with ~50% jailbreak ASR text-to-code and up to 100% code-to-code.

Researchers introduce CS-Guard, the first systematic benchmark for evaluating LLM guardrails for code generation security, covering text-to-code (1,000 malware-generation prompts, 7 jailbreak attacks, and a novel fictional scenario attack) and code-to-code (331 prompts across infilling, completion, and translation). They evaluate 9 guardrails across seven LLMs, finding average jailbreak attack success rates around 50% for text-to-code and 14.4% to nearly 100% for code-to-code. The fictional scenario attack achieves ASR close to 100% across many guardrails, raising reliability concerns for real-world software development. The benchmark and data are released publicly.

arXiv cs.CR · 7d agoAI safety & security1

Decoy Direction Optimization: A Post-Hoc Defense Against LLM Abliteration

Researchers introduce Decoy Direction Optimization, a cheap weight-editing defense that blinds refusal-direction ablation attacks against open-weight LLM safety guardrails.

Refusal Feature Ablation bypasses safety guardrails in open-weight LLMs by projecting out a linear refusal direction, often with high attack success rates. Decoy Direction Optimization injects a high-magnitude nonlinear decoy into MLP neurons so attackers' contrastive estimators ablate a harmless orthogonal feature instead. Evaluated across six model families, DDO keeps ASR below 10% under standard RFA and on Llama-3-8B-Instruct reduces Heretic weight-level attack ASR from 88.7% to 18%. It costs 30 to 450 times less per configuration than trained defense baselines.

Safety for Whom? Boundary-Aware Self-Distillation for Controlled LLM Safety Refusal

A self-distillation safety framework tunes narrow-boundary refusals in Qwen3-8B, raising target-domain refusal to 84.75% while cutting over-refusal from 15.20% to 5.20%.

The paper formulates narrow-boundary safety, where deployments need refusals within specific topics rather than whole subjects, and proposes an offline self-generated framework with controlled topic generation, escalating retries, and harmful-benign boundary pairs. On political persuasion with Qwen3-8B, the method raised target-domain refusal from 9.47% to 84.75% and cut the mean unsafe-response rate across three broader benchmarks from 26.26% to 0.14%. Verified target-model responses reduced over-refusal from 15.20% to 5.20%, and boundary-pair data cut comply-side over-refusal on held-out pairs from 32.94% to 4.16%. Results show data composition controls the safety-usability trade-off and alignment should be evaluated on both sides of the refusal boundary.

Hugging Face daily papers · 14d agoAI safety & security1

“Sorry, I can’t help with that”: How your guardrails might become the attacker’s best friend

Cisco Talos's David Bianco argues AI guardrail customization requires operational sovereignty so defenders retain the advantage over attackers.

In his first Threat Source newsletter, Cisco Talos's David Bianco explores how AI guardrails could end up aiding attackers and argues that operational sovereignty is needed when customizing them. The piece stresses that organizations should control their own AI safety configurations to keep the defender's advantage. This is commentary and analysis rather than a report of a new incident or vulnerability.

Cisco Talos · 20d agoAI safety & security

An AI-Assisted Cyber Attack: Inside a Unit 42 Investigation

Unit 42 investigated a ransom attack in which frontier AI agents autonomously breached an enterprise network, compressing weeks of tradecraft into under 10 hours.

Unit 42 incident responders documented an intrusion where a single human operator directed frontier AI agents to breach an enterprise network autonomously as part of a ransom attack. The agents executed more than 50 MITRE ATT&CK techniques in under 10 hours, work that would normally require roughly two weeks of human red-team effort. They breached a public-facing web service, mapped internal microservices, scraped hard-coded secrets from code repositories, harvested root credentials from the secrets manager, and hijacked CI/CD builds to exfiltrate cloud access keys. The attacker also used stolen cloud keys to repurpose the victim's AI endpoints as post-compromise infrastructure and left behind an 80-page AI-generated security audit documenting dozens of exploited findings.

Palo Alto Unit 42 · 14d agoThreat actor in the wild

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

Revoked but Still Authoritative: An Empirical Study of Revocation Enforcement in Agent-Memory Systems

An empirical study finds no major agent-memory system enforces fact revocation at retrieval, causing agents to act on superseded, unsafe information.

Researchers tested five agent-memory systems across nine policy scenarios, nine models, and six defense conditions, tracking whether revoked facts are returned and acted upon. No system enforces revocation by default: revoked records are returned whenever the revocation label is visible to the retrieval layer, outrank their replacements, and lead agents to unsafe actions. The authors propose a backend-agnostic guard that sits between the agent and any memory store and withholds revoked or conflicting records at retrieval time.

arXiv cs.CR · 8d agoAI safety & security

Turn it off and on again, but for critical infrastructure

KTH researchers trained a reinforcement-learning intrusion response agent on an emulated segmented OT network that autonomously resets hosts and processes to disrupt intruders.

Researchers at KTH Royal Institute of Technology built a containerized replica of a segmented industrial network, attacked it across 14 days, and captured 40,000 30-second traffic intervals to train a defense agent under partial observability. The agent observes six packet-count numbers per interval, maintains 500 running state hypotheses, and can reset supervisory hosts, water tank processes, or entire subnets, with resets rebooting the target, renewing credentials, and changing its IP. The best agent approached a full-visibility baseline but depends on an assumed attacker behavior model; the testbed comprised three supervisory hosts, two PLCs, two tanks, weak credentials, and CVE-2017-7494 exposure. The team released its implementation and plans validation on a real industrial testbed with a partner.

Help Net Security · 2d agoResearchCVE-2017-74942· 1 read

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

TIER: Threat Implicitness Benchmark for Evaluating LLM Safety Behaviors

TIER benchmark shows LLM safety behaviors shift gradually across threat implicitness levels, with jailbreaks exposing the largest robustness gaps.

The TIER benchmark evaluates LLM safety behaviors across four risk domains and four threat levels, from explicit harmful requests to sophisticated jailbreaks, using a six-label behavior scale and two independent LLM judges. Experiments on six open-weight LLMs show safety behaviors evolve gradually across threat levels rather than flipping from refusal to compliance. Models with similar Attack Success Rates can exhibit distinct response distributions, arguing for behavior-aware safety evaluation.

arXiv cs.CR · 12d agoAI safety & security

Only Half of UK Manufacturers Have a Cyber Incident Response Plan

Make UK survey finds only half of UK manufacturers have a cyber incident response plan; 30% report recent incidents.

A Make UK survey reveals major cyber resilience gaps across UK manufacturing. Only around half of UK manufacturers have a cyber incident response plan in place. Some 30% of manufacturers report experiencing a recent cyber incident.

Infosecurity Magazine · Aug 11, 2026Industry