Ransomware attacks and how victims respond

Welcome to this week's edition of the Threat Source newsletter. I count myself fortunate that I have never been on the receiving end of a ransomware attack. My experiences have been from research and response, never as a victim. It's a tough scenario: One day you are working or minding your own...

BeaverTail and OtterCookie evolve with a new Javascript module

Cisco Talos has uncovered a new attack linked to Famous Chollima, a threat group aligned with North Korea DPRK. This group is known for impersonating hiring organizations to target job seekers, tricking them into installing information-stealing malware to obtain cryptocurrency and user credential...

Too salty to handle: Exposing cases of CSS abuse for hidden text salting

Cisco Talos has been closely monitoring the abuse of cascading style sheets CSS properties to include irrelevant content or salt in different parts of messages, a technique known as hidden text salting. This blog is a follow-up to our previous reports in January and March 2025 on CSS abuse in...

Alex Ryan: From zero chill to quiet confidence

Welcome to another episode of Humans of Talos, our ongoing video interview series that celebrates the people powering Cisco's threat intelligence efforts. In each episode, we dive deep into the personal journeys, motivations and lessons learned from the team members who help keep the internet saf...

Microsoft Patch Tuesday for September 2025 – Snort rules and prominent vulnerabilities

Microsoft has released its monthly security update for September 2025, which includes 86 vulnerabilities affecting a range of products. In this month's release, Microsoft observed none of the included vulnerabilities being exploited in the wild. However, there are eight vulnerabilities where...

PDFs: Portable documents, or perfect deliveries for phish?

Cisco recently developed and released an update to its brand impersonation detection engine for emails. This new update enhances detection coverage and includes a wider range of brands that are delivered using PDF payloads or attachments. A significant portion of email threats with PDF payloads...

A week with a "smart" car

Welcome to this week's edition of the Threat Source newsletter. June 9 was Whit Monday -- a bank holiday here in Germany -- so I decided to take the whole week off. It turned out to be the perfect opportunity to try out a brand new car. Little did I know, I was about to get a crash course in mode...

When legitimate tools go rogue

Late one Tuesday night, Elena's phone buzzed with an alert from her company's SIEM. Her team had set up a rule to flag when certain system tools -- whoami, nltest and nslookup--were run one after another in quick succession. That exact pattern had just triggered on a computer in the Finance...

Year in Review: The biggest trends in ransomware

This week, our Year in Review spotlight is on ransomware --where low-profile tactics led to high-impact consequences. Ransomware operators often prioritized stealth over complexity for initial access. They also focused on slipping past defenses with minimal noise--uninstalling security tools,...

Who is Responsible and Does it Matter?

Welcome to this week's edition of the Threat Source newsletter. At Talos we bat on behalf of our customers, protecting them against all manner of cyber threats that may affect them. The nature of the threat actor and their origin or affiliation makes no difference; if they are attacking or planni...

Welcome to the party, pal!

Welcome to the final Threat Source newsletter of 2024. Watching "Die Hard" during the Christmas season has become a widely recognized tradition for many, despite ongoing debates about its classification as a Christmas movie. I know it isn't everyone's cup of tea. Whether you like the movie or not...

Watch our new documentary, "The Light We Keep: A Project PowerUp Story"

You may have already read about the incredible story of Project PowerUp - how we worked with a multi-company, multi-national team to find a way to keep the lights on in Ukraine in the face of electronic warfare. Today, we are releasing a short documentary on how this story came to be, while...

Threat Roundup for June 17 to June 24

Today, Talos is publishing a glimpse into the most prevalent threats we've observed between June 17 and June 24. 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...

Threat Source newsletter (June 9, 2022) — Get ready for Cisco Live

By Jon Munshaw. Welcome to this week’s edition of the Threat Source newsletter. Another week, another conference. We’re heading a few miles southeast from San Francisco to Las Vegas for Cisco Live. I hope everyone had a safe, healthy and enjoyable RSA, but the fun isn’t over just... This is only...

Threat Source Newsletter (Jan. 20, 2022)

Newsletter compiled by Jon Munshaw.Good afternoon, Talos readers. Even though we're nearly a month into 2022, we're still not quite ready to move on from 2021. That's why next week, we'll be going live on social media to talk about some of the top cybersecurity stories from the past... This is on...

Talos Takes Ep. #78: Attackers would love to buy you a non-existent PS5 this holiday season

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. We know this episode comes around every year, but people keep falling for scams, so we have to remind people how to... Thi...

Attracting flies with Honey(gain): Adversarial abuse of proxyware

By Edmund Brumaghin and Vitor Ventura. With internet-sharing applications, or "proxyware," users download software that allows them to share a percentage of their bandwidth with other internet users for a fee, with the companies that created this software acting as a go-between.As proxyware has...

Malicious Campaign Targets Latin America: The seller, The operator and a curious link

By Asheer Malhotra and Vitor Ventura, with contributions from Vanja Svajcer. Cisco Talos has observed a new malware campaign delivering commodity RATs, including njRAT and AsyncRAT.The campaign targets travel and hospitality organizations in Latin America.Techniques utilized in this campaign...

Threat Source Newsletter (May 6, 2021)

Newsletter compiled by Jon Munshaw. Good afternoon, Talos readers. COVID-19 has changed everything about our lives — no surprise there. So it also shouldn't be shocking that it's changing the way Americans view Tax Day this year. The deadline to file taxes is about a month later... This is only t...

Microsoft Patch Tuesday for April 2021 — Snort rules and prominent vulnerabilities

By Jon Munshaw, with contributions from Vanja Svajcer. Microsoft released its monthly security update Tuesday, disclosing 108 vulnerabilities across its suite of products, the most in any month so far this year. Four new remote code execution vulnerabilities in Microsoft Exchange Server are... Th...

Vulnerability Spotlight: Multiple vulnerabilities in OpenClinic’s GA web portal

Yuri Kramarz of Cisco Talos discovered these vulnerabilities. Blog by Jon Munshaw. Cisco Talos recently discovered multiple vulnerabilities in OpenClinic’s GA web portal. OpenClinic GA is an open-source, fully integrated hospital management solution. The web portal allows users to manage... This ...

Talos Takes Ep. #47: Looking back at the Masslogger trojan

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. We return to our usual formatting this week to discuss the Masslogger trojan. We covered this threat earlier this year...

Threat Roundup for February 5 to February 12

Today, Talos is publishing a glimpse into the most prevalent threats we've observed between Feb. 5 and Feb. 12. 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,...

Talos Takes Ep. #41: The tl;dr of Snort 3

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. This week's episode is for all our SNORTⓇ lovers out there. To celebrate last month's release of the Snort 3 GA, we have Nicholas Mavis on...

Microsoft Patch Tuesday for Sept. 2020 — Snort rules and prominent vulnerabilities

By Jon Munshaw. Microsoft released its monthly security update Tuesday, disclosing more than 120 vulnerabilities across its array of products. Twenty-three of the vulnerabilities are considered “critical" while the vast remainder are ranked as “important.” Users of all Microsoft and Windows...

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

Microsoft has released its monthly security update for September 2026, which includes 973 vulnerabilities affecting a range of products, including 113 that Microsoft marked as "critical." Microsoft notes that 2 of the vulnerabilities disclosed this month have been exploited in the wild:...

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...

[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...

This one’s for you, Mom

Welcome to this week's edition of the Threat Source newsletter. I am the product of a single parent, my mom, who along with my grandparents helped raise me into the man I am today. I cannot fathom what it took for my mom, who worked three jobs to put herself through college to be a teacher, to...

Lexi DiScola’s guide to global teamwork and overflowing TBRs

Welcome back to Humans of Talos. This month, Amy chats with Senior Cyber Threat Analyst Lexi DiScola from the Strategic Analysis team. Lexi's journey into cybersecurity is anything but traditional -- she brings a background in political science and French to her work tracking global cyber threats...

One newsletter to rule them all

Welcome to this week's edition of the Threat Source newsletter. " It's a dangerous business, going out your door. You step onto the road, and if you don't keep your feet, there's no knowing where you might be swept off to." -- Bilbo Baggins It's almost the end of the year, which feels like the...

Remember, remember the fifth of November

Welcome to this week's edition of the Threat Source newsletter. Ever heard the phrase in this week's title? For our non-British readers, here's the quick version: Every year on November 5, people across the U.K. gather for bonfires, sparklers, fireworks, and attempting to literally handle a hot...

Link up, lift up, level up

Welcome to this week's edition of the Threat Source newsletter. As summer retreats into the rear-view mirror, I'd like to take a moment to reflect on one of my favorite things about the cybersecurity profession: the community. Earlier this month, I attended Black Hat USA 2025 and DEF CON 33 in...

Meet Hazel Burton

Welcome to the first episode of Humans of Talos, a new video interview series that shines a spotlight on team members across Talos. Featuring their personal stories, career journeys and unique perspectives, you'll get an inside look into what it's like to work in our organization and the people w...

Do we still have to keep doing it like this?

Welcome to the first edition of the Threat Source newsletter for 2025. Upon returning to work this week from my Lindt chocolate reindeer coma, my first task was to write this newsletter. As I stared at a blank template hoping for inspiration to suddenly strike, I did what any security professiona...

The evolution and abuse of proxy networks

As long as we've had the internet, users have tried to obfuscate how and what they are connecting to. In some cases, this is to work around restrictions put in place by governments or a desire to access content that is not otherwise available in a given region. This is why technologies like VPNs...

The adventures of an extroverted cyber nerd and the people Talos helps to fight the good fight

Welcome to this week's edition of the Threat Source newsletter. I am unbelievably lucky to do the work that I do. My title is technically 'Senior Security Strategist'. It's a very fancy title, but basically: I get to research threats with my colleagues and friends to keep people safe here at Talo...

How LLMs could help defenders write better and faster detection

Most users will associate large language models LLMs like ChatGPT with answering basic questions or helping to write basics lines of text. But could these tools actually help defenders in the cybersecurity industry write more effective detection content? Several security researchers from across...

De-anonymizing ransomware domains on the dark web

By Paul Eubanks. We have developed three techniques to identify ransomware operators' dark websites hosted on public IP addresses, allowing us to uncover previously unknown infrastructure for the DarkAngels, Snatch, Quantum and Nokoyawa ransomware groups.The methods we used to identify the...

Threat Roundup for April 22 to April 29

Today, Talos is publishing a glimpse into the most prevalent threats we've observed between April 22 and April 29. 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... This is on...

Threat Roundup for March 18 to March 25

Today, Talos is publishing a glimpse into the most prevalent threats we've observed between March 18 and March 25. 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... This is on...

Threat Roundup for February 25 to March 4

Today, Talos is publishing a glimpse into the most prevalent threats we've observed between Feb. 25 and March 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...

Threat Source Newsletter (Jan. 13, 2022)

Newsletter compiled by Jon Munshaw.Good afternoon, Talos readers. Move out of the way, Log4j! Traditional malware is back with a bang in 2022. While Log4j is likely still occupying many defenders' minds, the bad guys are still out there doing not-Log4j things. We have new research out... This is...

Vulnerability Spotlight: Vulnerabilities in DaVinci Resolve video editing software could lead to code execution

A Cisco Talos team member discovered these vulnerabilities. Blog by Jon Munshaw. Cisco Talos recently discovered two vulnerabilities in the DaVinci Resolve video editing software that could allow an adversary to execute code in the context of the application. DaVinci Resolve is a... This is only...

Cisco named leader in Incident Response Services

By Brad Garnett. It has been more than two years already since Cisco Incident Response became a part of the Talos family. Since then, my team has continued a journey to simplify our offering for consumption and make incident response the ultimate team sport. That is why I could not be more... Thi...

Beers with Talos Ep. #102: Twitter has questions for us

Beers with Talos BWT Podcast episode No. 102 is now available. Download this episode and subscribe to Beers with Talos:Apple Podcasts Google PodcastsSpotify StitcherIf iTunes and Google Play aren't your thing, click here. By Mitch Neff. Recorded Feb. 23, 2021 We’ve been... This is only the...

Threat Source newsletter (Feb. 11, 2021)

Newsletter compiled by Jon Munshaw. Good afternoon, Talos readers. We have an update on LodaRAT, a trojan we’ve been following for years. This threat has a new version targeting Android devices, looking to infect devices and steal user’s credentials and monitor things like their phone calls and...

Beers with Talos EP42: To the Moon, Everyone!

Beers with Talos BWT Podcast Ep. 42 is now available. Download this episode and subscribe to Beers with Talos: If iTunes and Google Play aren't your thing, click here. Ep. 42 show notes: Recorded Nov. 16, 2018. Cyber moonshot, baby! It’s just like that time the U.S. raced everyone to the moon,...

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...

Talos Takes: 2025 insights from Talos and Splunk

In this episode of Talos Takes, Amy is joined by William Largent Cisco Talos and Lou Stella Splunk for a "double-header" discussion. With the recent release of the Cisco Talos 2025 Year in Review and the Splunk Top 50 Cybersecurity Threats report, we're breaking down the most critical trends that...