Henry IV, Hotspur, Hal, and hallucinations

Welcome to this week's edition of the Threat Source newsletter. " 'Tis dangerous to take a cold, to sleep, to drink; but I tell you, my lord fool, out of this nettle, danger, we pluck this flower, safety." - Hotspur, Shakespeare's Henry IV, Part 1: Act 2 Scene 3 I get it. Hotspur is the...

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

Microsoft has released its monthly security update for February 2026, which includes 59 vulnerabilities affecting a range of products, including two that Microsoft marked as "Critical". CVE-2026-21522 is a critical elevation of privilege vulnerability affecting Microsoft ACI Confidential...

Predicting 2026

Welcome to this week's edition of the Threat Source newsletter. It's become traditional at this time of year to make predictions about cybersecurity for the coming year. Obviously, no one has a crystal ball to predict the future, and if they did, they would be quietly making a fortune rather than...

Adios 2025, you won’t be missed

Welcome to this week's edition of the Threat Source newsletter. For us in America, we're in the holiday doldrums and things slow and/or shut down until the new year. At Cisco, we shut down the last week of the year to reset and recharge, and I've grown to be quite fond of it. I've worked plenty o...

Microsoft Patch Tuesday for November 2025 — Snort rules and prominent vulnerabilities

Microsoft has released its monthly security update for November 2025, which includes 63 vulnerabilities affecting a range of products, including 5 that Microsoft marked as "critical." Current intelligence shows that one of the important vulnerabilities, CVE-2025-62215, has already been detected i...

Velociraptor leveraged in ransomware attacks

Cisco Talos has confirmed that ransomware operators are leveraging Velociraptor, an open-source digital forensics and incident response DFIR tool that had not previously been definitively tied to ransomware incidents. We assess with moderate confidence that this activity can be attributed to thre...

UAT-8099: Chinese-speaking cybercrime group targets high-value IIS for SEO fraud

Cisco Talos is disclosing details on UAT-8099, a Chinese-speaking cybercrime group mainly involved in search engine optimization SEO fraud and theft of high-value credentials, configuration files, and certificate data. Cisco's file census and DNS analysis show affected Internet Information Servic...

Cherry pie, Douglas firs and the last trip of the summer

Welcome to this week's edition of the Threat Source newsletter. Diane, 2:01 p.m., August 21st. I've just returned from a remarkable journey through Seattle and the misty roads of the Olympic Peninsula. If you ever find yourself driving beneath those towering Douglas firs or dragged by your partne...

What happened in Vegas (that you actually want to know about)

Welcome to this week's edition of the Threat Source newsletter. Last week I flew 5,000 miles to Las Vegas for Black Hat USA. After navigating the casino carpet labyrinth and finding the only venue in Nevada that serves a proper English breakfast tea with milk lifesaver, I've decided Black Hat fee...

ReVault! When your SoC turns against you…

Talos reported 5 vulnerabilities to Broadcom and Dell affecting both the ControlVault3 Firmware and its associated Windows APIs that we are calling "ReVault". 100+ models of Dell Laptops are affected by this vulnerability if left unpatched. The ReVault attack can be used as a post-compromise...

Spam campaign targeting Brazil abuses Remote Monitoring and Management tools

Cisco Talos identified a spam campaign targeting Brazilian users with commercial remote monitoring and management RMM tools since at least January 2025. Talos observed the use of PDQ Connect and N-able remote access tools in this campaign. The spam message uses the Brazilian electronic invoice...

Lessons from Ted Lasso for cybersecurity success

Welcome to this week's edition of the Threat Source newsletter. "Be curious, not judgmental," Ted Lasso says, misattributing Walt Whitman. We forgive Ted because... well, he's Ted Lasso. If you've not watched the first season of Ted Lasso, there is a defining moment where Ted confronts a nefariou...

How do cryptocurrency drainer phishing scams work?

By Teoderick Contreras and Jose Hernandez of Splunk, with contributions from the Splunk Threat Research Team. Cryptodrainer scams have emerged as a significant threat in the cryptocurrency ecosystem, targeting unsuspecting individuals with the promise of easy profits while covertly siphoning thei...

Operation Celestial Force employs mobile and desktop malware to target Indian entities

By Gi7w0rm, Asheer Malhotra and Vitor Ventura. Cisco Talos is disclosing a new malware campaign called "Operation Celestial Force" running since at least 2018. It is still active today, employing the use of GravityRAT, an Android-based malware, along with a Windows-based malware loader we track a...

How are user credentials stolen and used by threat actors?

Youve no doubt heard the phrase, "Attackers dont hack anyone these days. They log on." By obtaining or stealing valid user account details, an attacker can gain access to a system, remain hidden, and then elevate their privileges to "log in" to more areas of the network. Unfortunately, the use of...

Recommendations that defenders can use from Talos’ Year in Review Report

The Talos Year in Review is available now and contains a wealth of insights about how the threat landscape has shifted in 2023. With new ransomware strains emerging from leaked source code, commodity loaders adding more reconnaissance measures to their belts, and geopolitical events influencing A...

$19 Stanely cups, fake Amazon Prime memberships all part of holiday shopping scams circulating

I know Im a little late to the party to hit the prime SEO for Black Friday, Cyber Monday and holiday shopping. But if I know the readers of this newsletter, everyone is far from done with their holiday shopping already after a few days. I also know Im far from the only person to warn consumers...

Video: Everything you need to know about ongoing state-sponsored attacks targeting network infrastructure across the globe

Cisco and Talos are continuing to track and research a series of ongoing cyber attacks and espionage targeting out-of-date and unpatched network hardware. In this video, Hazel Burton interviews Matt Olney and J.J. Cummings from Talos to discuss the "Jaguar Tooth" campaign the U.K. government and...

2022 Year in Review: Ransomware & Commodity Loaders Livestream Replay

Did you miss our livestream covering the ransomware and commodity loader section in the Cisco Talos Year in Review report? Join host Mitch Neff and special guests Aliza Johnson, Azim Khodjibaev, and Nick Biasini as they discuss Talos findings and experiences monitoring ransomware and commodity...

Ransomware and Commodity Loader Topic Summary Report: Cisco Talos Year in Review 2022

The ransomware space is dynamic, continually adapting to changes in the geopolitical environment, actions by defenders, and efforts by law enforcement, which increased in scope and intensity in 2022. This leads groups to rebrand under different names, shut down operations, and form new strategic...

Threat Source newsletter (Feb. 2, 2023): I bid you all adieu

Welcome to this weeks edition of the Threat Source newsletter. If you havent noticed yet weve had a few guest writers on this newsletter over the last few months. Alas my time covering the newsletter has ended and I leave you with one final edition. Have no fear, William Largent will be rounding...

2022 Year in Review Livestream

Did you miss our livestream focused on the Ukraine topics presented in the Cisco Talos Year in Review report? Join host Hazel Burton and special guests Kendall McKay, Nick Randolph, and Vanja Svajcer as they discuss Talos now-years-long critical infrastructure effort in Ukraine. Their breifing...

TEST-2022 Talos Year in Review Report-TEST

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Get a Loda This: LodaRAT meets new friends

LodaRAT samples were deployed alongside other malware families, including RedLine and Neshta. Cisco Talos identified several variants and altered versions of LodaRAT with updated functionality have been seen in the wild. Changes in these LodaRAT variants include new functionality allowing...

See Yourself in Cyber: A Cybersecurity Awareness Month recap

As yet another October comes to an end, so does another Cybersecurity Awareness Month. Since 2004 when the President of the United States and Congress declared October Cybersecurity Awareness Month, weve taken the time to share our cybersecurity knowledge with the broader general public year afte...

Threat Roundup for September 23 to September 30

Today, Talos is publishing a glimpse into the most prevalent threats weve observed between Sept. 23 and Sept. 30. As with previous roundups, this post isnt meant to be an in-depth analysis. Instead, this post will summarize the threats weve observed by highlighting key behavioral characteristics,...

Threat Source newsletter (Aug. 18, 2022) — Why aren't Lockdown modes the default setting on phones?

By Jon Munshaw. Welcome to this week’s edition of the Threat Source newsletter. As the data privacy landscape gets increasingly murky, app developers and device manufacturers are finding new ways to sure up users’ personal information. Of course, all users have to do is go out of their way to...

EMEAR Monthly Talos Update: Training the next generation of cybersecurity researchers

Cisco Talos and Cisco Secure have the latest edition of the Talos EMEAR Threat Update series out now, which you can watch above or over at this link, where Martin Lee and Hazel Burton talk about the cybersecurity skills gap that currently exists and how we can better train the next generation of...

Threat Roundup for May 20 to May 27

Today, Talos is publishing a glimpse into the most prevalent threats we've observed between May 20 and May 27. As with previous roundups, this post isn't meant to be an in-depth analysis. Instead, this post will summarize the threats we've observed by highlighting key behavioral characteristics,...

Threat Source newsletter (April 28, 2022) — The 2022 Cybersecurity Mock Draft

By Jon Munshaw. Welcome to this week’s edition of the Threat Source newsletter that’s going to be a little different, but bear with me. In honor of the NFL Draft starting this evening — an event that Cisco is helping to secure — I thought it’d be appropriate to look at building a... This is only...

Threat Source newsletter (March 31, 2022) — Is "Fortnite" a Metaverse?

By Jon Munshaw. Welcome to this week’s edition of the Threat Source newsletter. By now, anyone on the internet has pondered the question: “Is a hot dog a sandwich?” My two cents: Yes, absolutely. Now as we move into the new internet age and onto Web 3.0 and NFTs instead of... This is only the...

Threat Advisory: CaddyWiper

Overview Cybersecurity company ESET disclosed another Ukraine-focused wiper dubbed "CaddyWiper" on March 14. This wiper is relatively smaller than previous wiper attacks we've seen in Ukraine such as "HermeticWiper" and "WhisperGate," with a compiled size of just 9KB. The wiper discovered has...

Preparing for denial-of-service attacks with Talos Incident Response

By Yuri Kramarz. Over the years, several extorsion-style and politically motivated denial-of-service attacks increased and still pose a threat to businesses and organizations of any size that can find themselves in the crosshairs of various malicious campaigns. A detailed... This is only the...

Cisco stands on guard with our customers in Ukraine

As the Russia-led invasion intensifies, Ukraine is being attacked by bombs and bytes. Cisco is working around the clock on a global, company-wide effort to protect our customers there and ensure that nothing goes dark. Cisco Talos has taken the extraordinary step of directly operating security...

Beers with Talos, Ep. #116: Let's wade into the MuddyWater filled with Vipers

Beers with Talos BWT Podcast episode No. 116 is now available. Download this episode and subscribe to Beers with Talos: Apple Podcasts Google Podcasts Spotify StitcherRecorded Feb. 4, 2022. If iTunes and Google Play aren't your thing, click here. Most people... This is only the beginning! Please...

Threat Roundup for January 28 to February 4

Today, Talos is publishing a glimpse into the most prevalent threats we've observed between Jan. 28 and Feb. 4. As with previous roundups, this post isn't meant to be an in-depth analysis. Instead, this post will summarize the threats we've observed by highlighting key behavioral...

Vulnerability Spotlight: Memory corruption and use-after-free vulnerabilities in Foxit PDF Reader

Aleksandar Nikolic of Cisco Talos discovered these vulnerabilities. Blog by Jon Munshaw. Cisco Talos recently discovered a memory corruption and use-after-free vulnerability in the Foxit PDF Reader. Foxit PDF Reader is one of the most popular PDF document readers currently... This is only the...

Talos Takes Ep. #76: What is Kimsuky phishing around for?

By Jon Munshaw. The latest episode of Talos Takes is available now. Download this episode and subscribe to Talos Takes using the buttons below, or visit the Talos Takes page. Blog posts aren't just for sharing your darkest secrets from high school anymore. They're also used by attackers to... Thi...

Microsoft Patch Tuesday for Nov. 2021 — Snort rules and prominent vulnerabilities

By Jon Munshaw and Tiago Pereira. Microsoft released its monthly security update Tuesday, disclosing 56 vulnerabilities in the company’s various software, hardware and firmware offerings, including one that’s actively being exploited in the wild. November’s security update... This is only the...

Threat Source newsletter (Oct. 28, 2021)

Newsletter compiled by Jon Munshaw.Good afternoon, Talos readers. Most people know about chicken and waffles. But what about squirrel and waffles? They may not be the most appetizing brunch, but they are teaming up for one heck of a spam campaign. We have new research out... This is only the...

Threat Roundup for October 15 to October 22

Today, Talos is publishing a glimpse into the most prevalent threats we've observed between Oct. 15 and Oct. 22. As with previous roundups, this post isn't meant to be an in-depth analysis. Instead, this post will summarize the threats we've observed by highlighting key behavioral...

Vulnerability Spotlight: Vulnerabilities in Anker Eufy Homebase could lead to code execution, buffer overflows

Lilith of Cisco Talos discovered this vulnerability. Blog by Jon Munshaw. Cisco Talos recently discovered two vulnerabilities in the Anker Eufy Homebase. The Eufy Homebase 2 is the video storage and networking gateway that works with Anker’s Eufy Smarthome ecosystem. All Eufy... This is only the...

Threat Source newsletter (Sept. 30, 2021)

Newsletter compiled by Jon Munshaw.Good afternoon, Talos readers. In the latest example of attackers trying to capitalize on current headlines, we've spotted a group using the recent fervor around the Pegasus spyware to spread malware. We've detailed a campaign in which the... This is only the...

Threat Source newsletter (Sept. 23, 2021)

Newsletter compiled by Jon Munshaw.Good afternoon, Talos readers. The Russian APT Turla is one of the most notorious threat actors out there today. And they aren't stopping, recently adding a new backdoor to their arsenal that serves as a "last chance" to retain a foothold on victim... This is on...

Quarterly Report: Incident Response trends in Summer 2020

By David Liebenberg and Caitlin Huey. For the fifth quarter in a row, Cisco Talos Incident Response CTIR observed ransomware dominating the threat landscape. Infections involved a wide variety of malware families including Ryuk, Maze, LockBit, and Netwalker, among others. In a continuation of...

Barbervisor: Journey developing a snapshot fuzzer with Intel VT-x

By Cory Duplantis. One of the ways vulnerability researchers find bugs is with fuzzing. At a high level, fuzzing is the process of generating and mutating random inputs for a given target to crash it. In 2017, I started developing a bare metal hypervisor for the purposes of snapshot fuzzing:...

Threat Roundup for June 19 to June 26

Today, Talos is publishing a glimpse into the most prevalent threats we've observed between June 19 and June 26. As with previous roundups, this post isn't meant to be an in-depth analysis. Instead, this post will summarize the threats we've observed by highlighting key behavioral characteristics...

Updates to Snort setup guides

Our documentation on Snort 3 running on CentOS and the Snort Rules Writing guide to Snort 3. Thanks to community member Yaser for providing the updates. The Snort 3 guide now has expanded information on logging options — such as syslog and JSON. There is also a new performance optimization sectio...

Beers with Talos Ep. #83: The In-between, Vol. 4

Beers with Talos BWT Podcast episode No. 83 is now available. Download this episode and subscribe to Beers with Talos: If iTunes and Google Play aren't your thing, click here. By Mitch Neff. Recorded May 15, 2020 Prod. Note: Things are a hot mess right now and the team thinks that there are voice...

Vulnerability Spotlight: Two code execution vulnerabilities in Microsoft Excel

Marcin “Icewall” Noga of Cisco Talos discovered these vulnerabilities. Blog by Jon Munshaw. Cisco Talos researchers recently discovered two code execution vulnerabilities in Microsoft Excel. Microsoft released updates for these two bugs as part of their Patch Tuesday security update this week. Bo...