Welcome to this week’s edition of the Threat Source newsletter. Our goal is to get accurate threat intelligence to our audience as quickly as possible, with all the context you need to ask the right questions of your own environment: How at risk are we from this threat? Are we prepared for it? And what can we do about it? What you don’t often see is all the... well, frankly, “mess” involved in producing it. All the dead ends we followed until we could confirm those ends were as dead as a…
Infostealers can expose far more than passwords, including authenticated sessions that may let attackers bypass MFA. Flare explains how defenders can prioritize compromised identities, determine whether stolen access is still usable, and respond before it leads to account takeover. [...]
In this article Attack chain overviewCampaign scope and targetingMitigation and protection guidanceReferencesLearn more Microsoft Defender Experts is tracking an active malware campaign that uses counterfeit software-download websites to impersonate trusted vendors and distribute malicious installers. The campaign has targeted users looking to download popular software and has resulted in compromises across multiple organizations and industries, primarily affecting China-based operations of…
In a report published Tuesday, Kaspersky said it first discovered NodeRabbit on a system in Afghanistan and later identified variants on systems in Egypt and Ethiopia.
Microsoft has published details about a Windows malware campaign it calls TerminalFix. The social engineering used to infect people is very similar to what we’ve seen in ClickFix campaigns. A website visitor is presented with a fake Cloudflare CAPTCHA which, when clicked, secretly copies a malicious command to their clipboard. Then they receive instructions on what they need to do to “prove they are human,” when in reality they are being instructed to execute the malicious command. After…
While monitoring Mirage Kitten activity, we uncovered a previously undocumented malware family that we dubbed NodeRabbit. We identified the first sample on a system in Afghanistan. Further threat hunting revealed two additional, more advanced, variants: one on a system in Egypt and another on a system in Ethiopia. NodeRabbit is a cross-platform remote access trojan (RAT) built with Node.js. It targets Windows, Linux, and macOS. Its operators deliver it through spear-phishing messages on…
Introduction Beginning in 2024 Mandiant investigated a string of compromises affecting Brazilian financial services, retail, and eCommerce organizations. Google Threat Intelligence Group (GTIG) tracks this activity as BREEZE COMET (formerly UNC5669), a financially motivated threat actor specializing in manipulating payment systems and banking software in Brazil to conduct fraudulent transfers. This activity overlaps with operations publicly reported as Plump Spider and SHADOW-AETHER-064. In…
Introduction On Monday 2026-08-31, I used a link from a malicious Brazilian Portuguese email to infect a Windows host in my lab. This was a Guildma (Astaroth) malware infection. The link from the email is geofenced for Brazil, meaning that it would only deliver the malware if I checked it from a Brazil-based IP address. Otherwise, it would send a legitimate installer (in this case for Android Studio) and not the malware. Furthermore, my web browser and operating system needed to use Brazilian…
Research by: hasherezade Key Points Since early 2025, Check Point Research has been tracking JSCeal, a sophisticated cryptocurrency-focused stealer with broader credential-theft, surveillance, and traffic-interception capabilities, delivered as compiled V8 bytecode (JSC files). The payloads are protected with javascript-obfuscator, using multiple techniques including RC4-protected strings, control-flow flattening, proxy functions, and operation wrappers. Our goal was to recover the code to a…
Learn how the Spring Ring campaign abuses Microsoft Teams and voice phishing to deploy malware and target enterprise domain controllers. The post Spring Ring: An Inside Look at Voice Phishing Campaigns in Microsoft Teams appeared first on Unit 42.
Attackers typically try to pass off malware as legitimate applications or as potentially unwanted programs that users deliberately search for and download, such as cheats or cracks. They often rely on ad and affiliate networks to deliver their creations to victims’ devices. This post examines a less conventional case: a well-known backdoor distributed under the guise of adware. The attackers may have chosen this distribution method because the adware was signed by the developer. On top of that,…
Group-IB uncovers BraZetsu, a new Python-based Windows malware that serves as a master toolkit for Initial Access Brokers and powers a unique, AI-enhanced underground marketplace for commercializing compromised Iberian and Latin American targets.
Multiple extensions for Google Chrome and Microsoft Edge delivered a malware framework that deployed modules to steal cryptocurrency, sensitive data, and browser history, as well as inject ClickFix lures. [...]
During my last FOR610 session, a student asked me if I had some statistics in mind about the compilers used to generate malicious PE files? A couple of months ago, I shared some stats about the trend in 64bits VS. 32bits malware[1]. Can we go a bit further? I (vibe-)coded a Python script based on the pefile library[2] to extract some info from the PE headers. Indeed, the PE file format contains a lot of metadata! They can be accessed using a lot of tools, like Detect It Easy: Note: When you…
Key Takeaways The DFIR Report Offerings Check out our Products here and our Services here. Want a demo, more information on our services, pricing or just want to chat? Get in Touch Contact us today for pricing or a demo! Case Summary In March 2026, our team identified an SEO poisoning campaign leading to malware deployment […] The post BengalSEO Part 1: Anatomy of the Operation appeared first on The DFIR Report.
Key Takeaways This case was first reported to customers in a threat brief released in July 2025 and in a public flash alert in August 2025 in partnership with Swisscom B2B CSIRT, which observed another intrusion tied to the same campaign. This report contains data from both intrusions. We plan to release a DFIR Labs […] The post From Bing Search to Ransomware: Bumblebee and AdaptixC2 Deliver Akira appeared first on The DFIR Report.
Key Takeaways We identified an exposed server that provided unusual visibility into a large-scale, multi-victim exploitation and collection operation. Artifacts on the host showed that Claude Code and OpenClaw were embedded in the operator’s day-to-day workflow, supporting troubleshooting, orchestration, and refinement of the collection pipeline. This AI-assisted workflow resulted in the modular platform Bissa scanner […] The post Bissa Scanner Exposed: AI-Assisted Mass Exploitation and…