DISCARDED: Tales From the Threat Research Trenches

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Host Selena Larson is joined by co-host Sarah Sabotka, along with returning guest Greg Lesnewich, Principal Threat Research Engineer, and Staff Threat Researcher Mark Kelly, for a follow-up to last episode's half-click deep dive — this time tracking how the technique is spreading beyond TA458 and TA488 into a brand-new Chinese cluster.
Greg picks up where last week left off with TA488 (aka Void Blizzard, aka Laundry Bear): after going quiet in February following exposure, the group resurfaced on July 22 — one day before Proofpoint's joint advisory with the NSA — with a new half-click exploit against Microsoft Outlook Web Access. The payload, a previously unseen browser-resident implant called OWAReaper, is built for persistence: it survives credential rotation, browser restarts, and even a full device reimage, and it phones home via GitHub commit messages and image requests proxied through legitimate CDNs like Slack and WordPress.
Mark then brings a new actor into the half-click conversation: UNK_MassTraction, a suspected China-aligned cluster exploiting a cross-site scripting flaw in Roundcube to target physics and engineering departments at North American universities — chosen, it turns out, specifically because they were running vulnerable Roundcube instances. The infection chain drops either a webshell or VShell, a Linux backdoor of murky, possibly commercially-developed origin that keeps popping up across Chinese state-sponsored intrusions.
The conversation covers:
How OWAReaper's persistence differs from anything Greg's seen before — including "poisoning" a user's other emails to reinfect the browser on every new tab
Why Greg's assessment of TA488 shifted from "less capable than TA458" to "neck and neck" after seeing this campaign
How Mark and Greg discovered UNK_MassTraction independently, within hours of each other
Why UNK_MassTraction's targets were all running vulnerable Roundcube — evidence of deliberate reconnaissance, not spray-and-pray
IceCube, the Roundcube stealer with telltale signs of LLM-assisted development
Why mail servers are functionally edge devices, and what that means for defenders who can't run EDR on them
Whether AI is accelerating adversary tradecraft on both the Russian and Chinese sides
The ethics of publishing offensive research on a live, evolving technique
The funniest (and most unsettling) lure email of the year: "Hi fellow, I really liked your vibe..."
Plus: Gus the dog's podcast debut, security awareness training in a world where opening an email can be enough, and shoutouts to Tom Lancaster (Volexity) and Microsoft's patch team.
Resources Mentioned:
Cleaning Out Inboxes: TA488 Comes for Outlook with Another Half-Click Exploit
TA488 Targets Zimbra Mailservers with Half-Click Exploits
One Email Closer to the Edge: UNK_MassTraction & the Physics of Exploitation
For more information about Proofpoint, check out our website.
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Hello to all our cyber roosters!
Host Selena Larson is joined by co-host Sarah Sabatka and returning guest Greg Lesnewich, Principal Threat Researcher at Proofpoint, to unpack two new reports on Russian aligned espionage actors abusing “half-click” exploits, which are vulnerabilities that compromise a target the moment they open an email in a vulnerable webmail viewer, no link or attachment required.
Greg breaks down the two distinct actors covered in Proofpoint's research: TA458, a mature, well-resourced group active across multiple webmail platforms (Zimbra, MDaemon, Roundcube, SOGo, and Horde) primarily targeting Ukraine, Eastern Europe, and militaries/ministries of foreign affairs; and TA488 (aka Void Blizzard, aka Laundry Bear), a comparatively scrappier contractor operation that leaned on a single Zimbra zero-day dubbed “ZimReaper” to steal credentials, full mailboxes, and up to 90 days of email history from Ukrainian government and U.S. targets.
The conversation covers how the half-click technique works under the hood (stored cross-site scripting via mishandled JavaScript event handlers in webmail HTML), how it differs from traditional phishing, the evidence pointing to a possible link between TA458 and GRU Unit 20728, why TA488's contractor status may explain its skittishness (burning down infrastructure after being outed) versus TA458's higher risk tolerance (including repeatedly firing exploits at targets that weren't even running vulnerable software), and what defenders running Zimbra, Roundcube, or similar platforms can actually do about it.
Resources Mentioned:
https://www.proofpoint.com/us/blog/threat-insight/ta458-roundpress-exploits
https://www.proofpoint.com/us/blog/threat-insight/ta488-targets-zimbra-mailservers-half-click-exploits
For more information about Proofpoint, check out our website.
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Hello to all our Cyber Pals!
Host Selena Larson is joined by Golo Mühr, Malware Reverse Engineer, X-Force Threat Intelligence and Kyle Cucci (Staff Threat Researcher, Proofpoint) to break down the joint research that helped power a major Operation Endgame disruption. 
Coordinated by Europol, the operation hit 66 domains and 296 servers tied to StealC and its close cousin Amadey, and led to the seizure of more than 25.6 million unique credentials stolen from over 385,000 compromised sites.

In this episode, Golo and Kyle take us inside the investigation:
How they built a custom StealC emulator to impersonate infected bots, talk to live C2 servers, and pull down real second-stage payloads
The tangled relationship between StealC and Amity, and how shared panels and configs let researchers cluster affiliates together
Why StealC sometimes delivers... more StealC (spoiler: probably not a masterplan)
A juicy case of "no honor among thieves" — evidence that one affiliate exploited a panel vulnerability to steal from other affiliates
The one confirmed instance of StealC delivering LockBit Black ransomware, caught in the wild via emulation
Why info stealers have become so attractive to threat actors compared to ransomware — lower risk, easier monetization, less law enforcement heat (until now)
What "success" actually looks like in a takedown, and why Kyle's proposed "pyramid of pain" for disruptions puts arrests at the top and infrastructure takedowns at the base
Plus: fake software downloads, sketchy YouTube game-crack links, public-private collaboration with law enforcement, and a well-earned shoutout to Proofpoint's Isaac for calling this threat over a decade ago.
Tune in for a deep dive into how threat intel teams track, emulate, and ultimately help dismantle one of the internet's most active credential-theft operations.

Resources Mentioned:

https://www.proofpoint.com/us/blog/threat-insight/stealc-you-later-proofpoint-and-ibm-x-force-support-operation-endgame

https://www.proofpoint.com/us/blog/threat-insight/threat-actors-deliver-malware-youtube-video-game-cracks

For more information about Proofpoint, check out our website.
 

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Hello to all our Cyber Pals! This week, we present a special replay of "Only Malware in the Building," the podcast that our host, Selena Larson, also co-hosts! Enjoy!

Welcome in! You’ve entered, Only Malware in the Building. Join us each month to sip tea and solve mysteries about today’s most interesting threats. Your host is ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠Selena Larson⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠, ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠Proofpoint⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ intelligence analyst and host of their podcast ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠DISCARDED⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠. Inspired by the residents of a building in New York’s exclusive upper west side, Selena is joined by her co-hosts ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠N2K Networks⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠Dave Bittner⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ and ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠Keith Mularski⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠, former FBI cybercrime investigator and now Chief Global Ambassador at ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠Qintel⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠.
Being a security researcher is a bit like being a detective: you gather clues, analyze the evidence, and consult the experts to solve the cyber puzzle. This week, our hosts dive into the evolving threat of software supply chain attacks and the growing risks facing the open-source ecosystem. As developers increasingly rely on third-party packages and AI-powered coding tools, attackers are finding new ways to abuse trusted software to reach a wider range of targets. The discussion explores why these attacks are becoming more common, what recent incidents reveal about the state of software security, and what organizations can do to better protect themselves.

Sources:  ⁠

Shai-Hulud worm returns stronger and more automated than ever before⁠
‘Mini Shai-Hulud’ malware compromises hundreds of open-source packages in sprawling supply-chain attack⁠
What We Learned: Axios NPM Supply Chain Compromise Emergency Briefing
Your AI Gateway Was a Backdoor: Inside the LiteLLM Supply Chain Compromise

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Hello to all our Cyber Pals!
Host Selena Larson is joined by Sean Farrell, Assistant General Counsel at Microsoft's Digital Crimes Unit (DCU), to pull back the curtain on how major cyber crime takedowns actually happen and how Microsoft uses civil lawsuits, criminal referrals, and global partnerships to disrupt some of the most damaging cyber crime operations in the world.
They discuss:
What DCU does and Sean's path from FBI to AWS to Microsoft
How civil claims like the CFAA and RICO are used to seize infrastructure
The Fox Tempest takedown and its ties to Rhysida ransomware
The global disruption of the Tycoon 2FA phishing-as-a-service operation
How targets get chosen, and civil vs. criminal action
Why naming victims changes the public narrative on cyber crime
Arrests tied to Octo Tempest/Scattered Spider
The risks of AI-generated sloppiness in legal and threat intel work
Disrupting cyber crime isn't about ending it for good, it's about raising the cost of doing business until bad actors run out of road.

Resources Mentioned:

https://www.microsoft.com/en-us/corporate-responsibility/customer-security-trust/digital-crimes-unit
https://blogs.microsoft.com/on-the-issues/2026/05/19/disrupting-fox-tempest-a-cybercrime-service/
https://www.proofpoint.com/us/blog/threat-insight/disruption-targets-tycoon-2fa-popular-aitm-phaas

For more information about Proofpoint, check out our website.
 

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