Reporting from Vegas: Networking, AI, and good boys

Welcome to this week's edition of the Threat Source newsletter. Howdy friends, and hello from Cisco Live U.S., here in sunny and very hot Las Vegas! An interesting quirk of being sent to one of these events is you learn to understand your limits as a person. Cisco Live is a three-day event, and i...

Winning the cyber marathon with Tony Giandomenico

In the high-speed world of cybersecurity, the difference between a breach and a breakthrough often comes down to endurance. Tony Giandomenico, Senior Director of Product Management with Cisco Talos, joins me to discuss how he balances the intensity of leading major product launches with the...

Hypotheses, telemetry, and human judgment: Inside Cisco Talos Threat Hunting

By Ron Scott-Adams Most security tools operate on a simple principle: If a known-bad pattern appears, fire an alert. This works well enough for many threats, but it fails against adversaries who closely study detection thresholds and deliberately stay under them. Cisco Talos Threat Hunting operat...

Less panic patching, more precision

Welcome to this week's edition of the Threat Source newsletter. Recently, Martin closed his introduction with a warning: Ready or not, the time of much patching is coming. I've been chewing on that one for a while because I'm rethinking my own enrichment pipelines along these lines, and the...

DICOM, Pydicom, GDCM, and Orthanc: A technical tour of what really happens in the heap

Over the last decade, DICOM parsing has become an active research topic. The reason is simple: DICOM is both critical and complicated. Hospitals rely on DICOM-based PACS systems, and those systems often automatically ingest files received over the network. That means malformed data could directly...

MediaArea heap-based buffer overflow vulnerabilities

Cisco Talos' Vulnerability Discovery & Research team recently disclosed four vulnerabilities in MediaArea MediaInfoLib library. The vulnerabilities mentioned in this blog post have been patched by their respective vendor, in adherence to Cisco 's third-party vulnerability disclosure policy. For...

Introducing EvidenceForge: Synthetic security logs that don’t look (as) fake

Security teams need high-quality, labeled datasets to train threat hunters and incident responders, validate detection logic, and develop robust analytic models. EvidenceForge helps teams overcome the limitations of anonymized or stale public datasets, while avoiding the cost and complexity of...

The art of being ungovernable

Welcome to this week's edition of the Threat Source newsletter. " It takes very little to govern good people. Very little. And bad people can't be governed at all. Or if they could, I never heard of it." ― Cormac McCarthy, No Country for Old Men Most of my career has been built on dichotomy:...

TP-Link, Photoshop, OpenVPN, Norton VPN vulnerabilities

Cisco Talos' Vulnerability Discovery & Research team recently disclosed eight vulnerabilities in TP-Link, and one each in Adobe Photoshop, OpenVPN, and Gen Digital's Norton VPN. The vulnerabilities mentioned in this blog post have been patched by their respective vendors, in adherence to Cisco 's...

From PDB strings to MaaS: Tracking a commodity BadIIS ecosystem used by Chinese-speaking threat

Cisco Talos has uncovered a BadIIS variant -- identifiable by its embedded "demo.pdb" strings -- that functions as commodity malware. This variant is likely sold or shared among multiple Chinese-speaking cybercrime groups that operate under a malware-as-a-service MaaS model for continuous...

The time of much patching is coming

Welcome to this week's edition of the Threat Source newsletter. Many solutions have been proposed to reduce software bugs: zero-defect mandates, pair programming, formal methods, and mathematical software proofs. The reality is that software engineering is hard. Identifying and fixing bugs before...

Ongoing exploitation of Cisco Catalyst SD-WAN vulnerabilities

Cisco Talos is tracking the active exploitation of CVE-2026-20182, an authentication bypass vulnerability in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, and Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage. Successful exploitation of CVE-2026-20182 allows an unauthenticated,...

Breaking things to keep them safe with Philippe Laulheret

In the latest Humans of Talos, Amy sits down with Senior Vulnerability Researcher Philippe Laulheret to demystify the world of ethical hacking. Philippe shares his unique journey from French engineering school to the front lines of cybersecurity, explaining how his lifelong love for solving puzzl...

Microsoft Patch Tuesday for May 2026 — Snort rules and prominent vulnerabilities

By Jaeson Schultz Microsoft has released its monthly security update for May 2026, which includes 137 vulnerabilities affecting a range of products, including 31 that Microsoft marked as "critical". In this month's release, Microsoft has not observed any of the included vulnerabilities being...

State-sponsored actors, better known as the friends you don’t want

State-sponsored actors don't break in. They log in, and they use your own tools to stay invisible for months. Responding to a state-sponsored threat is nothing like responding to ransomware, and the differences can make or break the outcome. From logging and baselines to OT segmentation and suppl...

Unplug your way to better code

Welcome to this week's edition of the Threat Source newsletter. Hey, you. Yeah, you! The person endlessly scrolling or typing away at their computer. Did you touch grass today? It's just an expression, but if nature's your thing, that works just fine. What I do mean is that due to the nature of t...

Insights into the clustering and reuse of phone numbers in scam emails

Cisco Talos has recently started to collect and gather intelligence around phone numbers within emails as an additional indicator of compromise IOC. In this blog, we discuss new insights into in-the-wild phone number reuse in scam emails. According to Talos' observations, the ease of API-driven...

UAT-8302 and its box full of malware

Cisco Talos is disclosing UAT-8302, a sophisticated, China-nexus advanced persistent threat APT group targeting government entities in South America since at least late 2024 and government agencies in southeastern Europe in 2025. After successful compromises, UAT-8302 deploys multiple custom-made...

CloudZ RAT potentially steals OTP messages using Pheno plugin

Cisco Talos discovered an intrusion, active since at least January 2026, where an unknown attacker implanted a CloudZ remote access tool RAT and a previously undocumented plugin called "Pheno." According to the functionalities of the CloudZ RAT and Pheno plugin, this was with the intention of...

Great responsibility, without great power

Welcome to this week's edition of the Threat Source newsletter. As I'm writing this, today April 28 is International Superhero Day. If you don't know the origin story behind this, perhaps you would assume that this day was dreamed up by Marvel. And… you would be correct. However, it's not a pure...

AI-powered honeypots: Turning the tables on malicious AI agents

Generative AI allows defenders to instantly create diverse honeypots, like Linux shells or Internet of Things IoT devices, using simple text prompts. This makes deploying complex, convincing deceptive environments much easier and more scalable than traditional methods. AI-driven attacks often...

Five defender priorities from the Talos Year in Review

A familiar theme in security right now is that the barrier to entry for attackers is at an all-time low. AI tools can spin up websites within minutes that can easily direct data to disposable external data stores and send alerts for new captures -- all without code. One such case was recently...

It pays to be a forever student

Welcome to this week's edition of the Threat Source newsletter. If I haven't said it in a newsletter before, I'll say it now: If you want to be good at cybersecurity, be a forever student. Cultivating and feeding your desire to know how things work is one of the key ingredients to being a hacker...

UAT-4356's Targeting of Cisco Firepower Devices

Cisco Talos is aware of UAT-4356's continued active targeting of Cisco Firepower devices' Firepower eXtensible Operating System FXOS. UAT-4356 exploited n-day vulnerabilities CVE-2025-20333 and CVE-2025-20362 to gain unauthorized access to vulnerable devices, where the threat actor deployed their...

IR Trends Q1 2026: Phishing reemerges as top initial access vector, as attacks targeting public administration persist

Phishing reemerged as the most observed means of gaining initial access, accounting for over a third of the engagements where initial access could be determined. Phishing has not been the top vector for initial access since Q2 2025. Public administration and health care tied as the most targeted...

[Podcast] It's not you, it's your printer: State-sponsored and phishing threats in 2025

!\Podcast\ It's not you, it's your printer: State-sponsored and phishing threats in 2025https://storage.ghost.io/c/af/a0/afa04ee3-414f-4481-8d23-7e7c146f192e/content/images/2026/04/YiR2025cover2x1-2-1.jpg In this episode, we unpack state-sponsored and phishing trends from the 2025 Talos Year in...

Phishing and MFA exploitation: Targeting the keys to the kingdom

In 2025, attackers increasingly targeted weaknesses in multi-factor authentication MFA workflows, and phishing attacks leveraged valid, compromised credentials to launch lures from trusted accounts. The trends focused entirely on trust, or the lack thereof, in everyday business operations. Phishi...

Bad Apples: Weaponizing native macOS primitives for movement and execution

As macOS adoption grows among developers and DevOps, it has become a high value target; however, native "living-off-the-land" LOTL techniques for the platform remain significantly under-documented compared to Windows. Adversaries can bypass security controls by repurposing native features like...

Foxit, LibRaw vulnerabilities

Cisco Talos' Vulnerability Discovery & Research team recently disclosed one Foxit Reader vulnerability, and six LibRaw file reader vulnerabilities. The vulnerabilities mentioned in this blog post have been patched by their respective vendors, all in adherence to Cisco 's third-party vulnerability...

The Q1 vulnerability pulse

Welcome to this week's edition of the Threat Source newsletter. The first quarter of 2026 passed faster than a misconfigured firewall rule gets exploited -- and the last few weeks have been firmly stamped with the "software supply chain compromise" label, with headlines surrounding incidents...

PowMix botnet targets Czech workforce

Cisco Talos discovered an ongoing malicious campaign, operating since at least December 2025, affecting a broader workforce in the Czech Republic with a previously undocumented botnet we call "PowMix." PowMix employs randomized command-and-control C2 beaconing intervals, rather than persistent...

More than pretty pictures: Wendy Bishop on visual storytelling in tech

In this episode of Humans of Talos, Amy sits down with Wendy Bishop, Head of Creative, to explore the vital role of design in the world of cybersecurity. From her early beginnings in web design and journalism to leading the creative vision for Talos, Wendy shares the unique challenges and rewards...

The n8n n8mare: How threat actors are misusing AI workflow automation

Cisco Talos research has uncovered agentic AI workflow automation platform abuse in emails. Recently, we identified an increase in the number of emails that abuse n8n, one of these platforms, from as early as October 2025 through March 2026. In this blog, Talos provides concrete examples of how...

Microsoft Patch Tuesday for April 2026 - Snort Rule and Prominent Vulnerabilities

Microsoft has released its monthly security update for April 2026, which includes 165 vulnerabilities affecting a wide range of products, including eight Microsoft marked as "critical." CVE-2026-23666 is a critical Denial of Service DoS vulnerability that affects the .NET framework. Successful...

State-sponsored threats: Different objectives, similar access paths

Across the Talos 2025 Year in Review, state-sponsored threat activity from China, Russia, North Korea, and Iran all had varying motivations, such as espionage, disruption, financial gain, and geopolitical influence. But when you look at how these operations actually unfold, similar tactics,...

[Video] The TTP Ep. 22: The Collapse of the Patch Window

!\Video\ The TTP Ep. 22: The Collapse of the Patch Windowhttps://storage.ghost.io/c/af/a0/afa04ee3-414f-4481-8d23-7e7c146f192e/content/images/2026/04/YiR2025cover2x1-3.jpg One of the clearest trends in the 2025 Talos Year in Review is just how quickly vulnerabilities are now being turned into...

The threat hunter’s gambit

Welcome to this week's edition of the Threat Source newsletter. " Study hard what interests you the most in the most undisciplined, irreverent and original manner possible." ― Richard Feynman " I had discovered that learning something, no matter how complex, wasn't hard when I had a reason to wan...

From the field to the report and back again: How incident responders can use the Year in Review

Every year, Cisco Talos publishes Year in Review, a comprehensive look at the previous year's threat landscape. It's drawn from an enormous volume of telemetry, such as endpoint detections, network traffic, email data, and boots-on-the-ground Cisco Talos Incident Response Talos IR engagements. As...

New Lua-based malware “LucidRook” observed in targeted attacks against Taiwanese organizations

Cisco Talos uncovered a cluster of activity we track as UAT-10362 conducting spear-phishing campaigns against Taiwanese non-governmental organizations NGOs and suspected universities to deliver a newly identified malware family, "LucidRook." LucidRook is a sophisticated stager that embeds a Lua...

Talos Takes: 2025's ransomware trends and zombie vulnerabilities

Join Amy and Pierre Cadieux as they unpack the ransomware and vulnerability trends that defined 2025. From the persistent ransomware threats targeting the manufacturing sector to the rise of stealthy living-off-the-land tactics, we break down what these shifts mean for your defense strategy. Why...

The Trojan horse of cybercrime: Weaponizing SaaS notification pipelines

By Diana Brown Cisco Talos has recently observed an increase in activity that is leveraging notification pipelines in popular collaboration platforms to deliver spam and phishing emails. These emails are transmitted using the legitimate mail delivery infrastructure associated with GitHub and Jira...

Year in Review: Vulnerabilities old and new and something React2

Speed and age shouldn't be allowed to pair up, but that is the theme of the Talos 2025 Year in Review vulnerability findings. Figure 1. React/React2Shell 2025 at the top, with PHPUnit 2017 and Log4j 2021 following up. The year was characterized by an unending beat-down on infrastructure that reli...

Do not get high(jacked) off your own supply (chain)

In the span of just a few weeks, we have observed a dizzying array of major supply chain attacks. Prominent examples include the malicious modification of Axios, a popular HTTP client library for JavaScript, as well as cascading compromises from TeamPCP, a "chaos-as-a-service" group that injected...

Axios NPM supply chain incident

Cisco Talos is actively investigating the March 31, 2026 supply chain attack on the official Axios node package manager npm package during which two malicious versions v1.14.1 and v0.30.4 were deployed. Axios is one of the more popular JavaScript libraries with as many as 100 million downloads pe...

The democratisation of business email compromise fraud

Welcome to this week's edition of the Threat Source newsletter. Last weekend, I witnessed a crime. Not a notable crime that you might read about in the press, but an unremarkable fraud attempt that nevertheless illustrates how new threat actor capabilities are emerging. I imagine that most people...

[Video] The TTP Ep 21: When Attackers Become Trusted Users

!\Video\ The TTP Ep 21: When Attackers Become Trusted Usershttps://storage.ghost.io/c/af/a0/afa04ee3-414f-4481-8d23-7e7c146f192e/content/images/2026/04/YiR2025cover2x1.jpg In this episode of the Talos Threat Perspective, we explore how identity is being used to gain, extend, and maintain access...

UAT-10608: Inside a large-scale automated credential harvesting operation targeting web applications

Cisco Talos is disclosing a large-scale automated credential harvesting campaign carried out by a threat cluster we are tracking as "UAT-10608." Post-compromise, UAT-10608 leverages automated scripts for extracting and exfiltrating credentials from a variety of applications, that are then posted ...

Qilin EDR killer infection chain

Endpoint detection and response EDR tools are widely deployed and far more capable than traditional antivirus. As a result, attackers use EDR killers to disable or bypass them. Disabling telemetry collection process, memory, network activity limits what defenders can see and analyze. As defenders...

Inside the Talos 2025 Year in Review: A discussion on what the data means for defenders

Every year, the Cisco Talos Year in Review captures the patterns shaping the threat landscape. The 2025 report paints a clear picture: Attackers are moving faster than ever, while using identity-related attacks as the primary battleground. To unpack the biggest takeaways and what they mean for...

An overview of ransomware threats in Japan in 2025 and early detection insights from Qilin cases

In 2025, a total of 134 ransomware incidents were reported in Japan, marking a 17.5% increase compared to 2024. Among these, 22 incidents were attributed to Qilin, representing 16.4% of the total. In 2025, Qilin ransomware was highly active. Looking ahead to 2026, unless there is significant...