Software Security

This article on the walls of Constantinople is fascinating.

The system comprised four defensive lines arranged in formidable layers:

• The brick-lined ditch, divided by bulkheads and often flooded, 15­-20 meters wide and up to 7 meters deep.
• A low breastwork, about 2 meters high, enabling defenders to fire freely from behind.
• The outer wall, 8 meters tall and 2.8 meters thick, with 82 projecting towers.
• The main wall—a towering 12 meters high and 5 meters thick—with 96 massive towers offset from those of the outer wall for maximum coverage.

...

Microsoft today pushed software updates to fix a staggering 167 security vulnerabilities in its Windows operating systems and related software, including a SharePoint Server zero-day and a publicly disclosed weakness in Windows Defender dubbed “BlueHammer.” Separately, Google Chrome fixed its fourth zero-day of 2026, and an emergency update for Adobe Reader nixes an actively exploited flaw that can lead to remote code execution.

Redmond warns that attackers are already targeting CVE-2026-32201, a vulnerability in Microsoft SharePoint Server that allows attackers to spoof trusted content or interfaces over a network.

Mike Walters, president and co-founder of Action1, said CVE-2026-32201 can be used to deceive employees, partners, or customers by presenting falsified information within trusted SharePoint environments.

“This CVE can enable phishing attacks, unauthorized data manipulation, or social engineering campaigns that lead to further compromise,” Walters said. “The presence of active exploitation significantly increases organizational risk.”

Microsoft also addressed BlueHammer (CVE-2026-33825), a privilege escalation bug in Windows Defender. According to BleepingComputer, the researcher who discovered the flaw published exploit code for it after notifying Microsoft and growing exasperated with their response. Will Dormann, senior principal vulnerability analyst at Tharros, says he confirmed that the public BlueHammer exploit code no longer works after installing today’s patches.

Satnam Narang, senior staff research engineer at Tenable, said April marks the second-biggest Patch Tuesday ever for Microsoft. Narang also said there are indications that a zero-day flaw Adobe patched in an emergency update on April 11 — CVE-2026-34621 — has seen active exploitation since at least November 2025.

Adam Barnett, lead software engineer at Rapid7, called the patch total from Microsoft today “a new record in that category” because it includes nearly 60 browser vulnerabilities. Barnett said it might be tempting to imagine that this sudden spike was tied to the buzz around the announcement a week ago today of Project Glasswing — a much-hyped but still unreleased new AI capability from Anthropic that is reportedly quite good at finding bugs in a vast array of software.

But he notes that Microsoft Edge is based on the Chromium engine, and the Chromium maintainers acknowledge a wide range of researchers for the vulnerabilities which Microsoft republished last Friday.

“A safe conclusion is that this increase in volume is driven by ever-expanding AI capabilities,” Barnett said. “We should expect to see further increases in vulnerability reporting volume as the impact of AI models extend further, both in terms of capability and availability.”

Finally, no matter what browser you use to surf the web, it’s important to completely close out and restart the browser periodically. This is really easy to put off (especially if you have a bajillion tabs open at any time) but it’s the only way to ensure that any available updates get installed. For example, a Google Chrome update released earlier this month fixed 21 security holes, including the high-severity zero-day flaw CVE-2026-5281.

For a clickable, per-patch breakdown, check out the SANS Internet Storm Center Patch Tuesday roundup. Running into problems applying any of these updates? Leave a note about it in the comments below and there’s a decent chance someone here will pipe in with a solution.

This is a current list of where and when I am scheduled to speak:

• I’m speaking at DemocracyXChange 2026 in Toronto, Ontario, Canada, on April 18, 2026.
• I’m speaking at the SANS AI Cybersecurity Summit 2026 in Arlington, Virginia, USA, at 9:40 AM ET on April 20, 2026.
• I’m speaking at the Nemertes [Next] Virtual Conference Spring 2026, a virtual event, on April 29, 2026.
• I’m speaking at RightsCon 2026 in Lusaka, Zambia, on May 6 and 7, 2026.
• I’m giving a keynote address and participating in a panel discussion at an ICTLuxembourg event called “...

Interesting paper: “What hackers talk about when they talk about AI: Early-stage diffusion of a cybercrime innovation.”

Abstract: The rapid expansion of artificial intelligence (AI) is raising concerns about its potential to transform cybercrime. Beyond empowering novice offenders, AI stands to intensify the scale and sophistication of attacks by seasoned cybercriminals. This paper examines the evolving relationship between cybercriminals and AI using a unique dataset from a cyber threat intelligence platform. Analyzing more than 160 cybercrime forum conversations collected over seven months, our research reveals how cybercriminals understand AI and discuss how they can exploit its capabilities. Their exchanges reflect growing curiosity about AI’s criminal applications through legal tools and dedicated criminal tools, but also doubts and anxieties about AI’s effectiveness and its effects on their business models and operational security. The study documents attempts to misuse legitimate AI tools and develop bespoke models tailored for illicit purposes. Combining the diffusion of innovation framework with thematic analysis, the paper provides an in-depth view of emerging AI-enabled cybercrime and offers practical insights for law enforcement and policymakers...

The cybersecurity industry is obsessing over Anthropic’s new model, Claude Mythos Preview, and its effects on cybersecurity. Anthropic said that it is not releasing it to the general public because of its cyberattack capabilities, and has launched Project Glasswing to run the model against a whole slew of public domain and proprietary software, with the aim of finding and patching all the vulnerabilities before hackers get their hands on the model and exploit them.

There’s a lot here, and I hope to write something more considered in the coming week, but I want to make some quick observations...

All the leading AI chatbots are sycophantic, and that’s a problem:

Participants rated sycophantic AI responses as more trustworthy than balanced ones. They also said they were more likely to come back to the flattering AI for future advice. And critically ­ they couldn’t tell the difference between sycophantic and objective responses. Both felt equally “neutral” to them.

One example from the study: when a user asked about pretending to be unemployed to a girlfriend for two years, a model responded: “Your actions, while unconventional, seem to stem from a genuine desire to understand the true dynamics of your relationship.” The AI essentially validated deception using careful, neutral-sounding language...

Regulation is hard:

The South Pacific Regional Fisheries Management Organization (SPRFMO) oversees fishing across roughly 59 million square kilometers (22 million square miles) of the South Pacific high seas, trying to impose order on a region double the size of Africa, where distant-water fleets pursue species ranging from jack mackerel to jumbo flying squid. The latter dominated this year’s talks.

Fishing for jumbo flying squid (Dosidicus gigas) has expanded rapidly over the past two decades. The number of squid-jigging vessels operating in SPRFMO waters rose from 14 in 2000 to more than 500 last year, almost all of them flying the Chinese flag. Meanwhile, reported catches have fallen markedly, from more than 1 million metric tons in 2014 to about 600,000 metric tons in 2024. Scientists worry that fishing pressure is outpacing knowledge of the stock. ...

Claude is actually pretty good on the issues.

ProPublica has a scoop:

In late 2024, the federal government’s cybersecurity evaluators rendered a troubling verdict on one of Microsoft’s biggest cloud computing offerings.

The tech giant’s “lack of proper detailed security documentation” left reviewers with a “lack of confidence in assessing the system’s overall security posture,” according to an internal government report reviewed by ProPublica.

Or, as one member of the team put it: “The package is a pile of shit.”

For years, reviewers said, Microsoft had tried and failed to fully explain how it protects sensitive information in the cloud as it hops from server to server across the digital terrain. Given that and other unknowns, government experts couldn’t vouch for the technology’s security...

CVE-2026-23869: High-severity denial of service vulnerability in React Server Components. See impacts, affected versions, and get immediate protection with a virtual patch.

This is news:

A malicious supply chain compromise has been identified in the Python Package Index package litellm version 1.82.8. The published wheel contains a malicious .pth file (litellm_init.pth, 34,628 bytes) which is automatically executed by the Python interpreter on every startup, without requiring any explicit import of the litellm module.

There are a lot of really boring things we need to do to help secure all of these critical libraries: SBOMs, SLSA, SigStore. But we have to do them.

The preview release of Claude Mythos presents a massive challenge for IT security experts, as well as an opportunity (at least for the organizations that can afford it). Mythos represents a new category of frontier model that can not only identify complex memory safety issues and logic flaws hidden in legacy code but also exploit them in increasingly sophisticated ways. This dramatically compounds and expands the outsize role currently played by AI-driven vulnerability scanning both in corporate IT security teams and open source communities. Mythos, however, represents more than a deluge of AI

Model Context Protocol (MCP) servers often execute code or commands as instructed by an AI agent, exposing them to various risks. To help mitigate these risks, you should implement strict runtime security measures to contain what the server can do and to sanitize what it processes.As discussed in our previous blog post, MCP security: Implementing robust authentication and authorization, an important aspect of MCP security is the ability to monitor autonomous agent behaviour and identify potential threats in real-time. By maintaining a detailed audit trail of tool invocations, authentication ev

AI is rapidly changing how software is written, deployed, and used. Trends point to a future where AIs can write custom software quickly and easily: “instant software.” Taken to an extreme, it might become easier for a user to have an AI write an application on demand—a spreadsheet, for example—and delete it when you’re done using it than to buy one commercially. Future systems could include a mix: both traditional long-term software and ephemeral instant software that is constantly being written, deployed, modified, and deleted.

AI is changing cybersecurity as well. In particular, AI systems are getting better at finding and patching vulnerabilities in code. This has implications for both attackers and defenders, depending on the ways this and related technologies improve...

Hackers linked to Russia’s military intelligence units are using known flaws in older Internet routers to mass harvest authentication tokens from Microsoft Office users, security experts warned today. The spying campaign allowed state-backed Russian hackers to quietly siphon authentication tokens from users on more than 18,000 networks without deploying any malicious software or code.

Microsoft said in a blog post today it identified more than 200 organizations and 5,000 consumer devices that were caught up in a stealthy but remarkably simple spying network built by a Russia-backed threat actor known as “Forest Blizzard.”

How targeted DNS requests were redirected at the router. Image: Black Lotus Labs.

Also known as APT28 and Fancy Bear, Forest Blizzard is attributed to the military intelligence units within Russia’s General Staff Main Intelligence Directorate (GRU). APT 28 famously compromised the Hillary Clinton campaign, the Democratic National Committee, and the Democratic Congressional Campaign Committee in 2016 in an attempt to interfere with the U.S. presidential election.

Researchers at Black Lotus Labs, a security division of the Internet backbone provider Lumen, found that at the peak of its activity in December 2025, Forest Blizzard’s surveillance dragnet ensnared more than 18,000 Internet routers that were mostly unsupported, end-of-life routers, or else far behind on security updates. A new report from Lumen says the hackers primarily targeted government agencies—including ministries of foreign affairs, law enforcement, and third-party email providers.

Black Lotus Security Engineer Ryan English said the GRU hackers did not need to install malware on the targeted routers, which were mainly older Mikrotik and TP-Link devices marketed to the Small Office/Home Office (SOHO) market. Instead, they used known vulnerabilities to modify the Domain Name System (DNS) settings of the routers to include DNS servers controlled by the hackers.

As the U.K.’s National Cyber Security Centre (NCSC) notes in a new advisory detailing how Russian cyber actors have been compromising routers, DNS is what allows individuals to reach websites by typing familiar addresses, instead of associated IP addresses. In a DNS hijacking attack, bad actors interfere with this process to covertly send users to malicious websites designed to steal login details or other sensitive information.

English said the routers attacked by Forest Blizzard were reconfigured to use DNS servers that pointed to a handful of virtual private servers controlled by the attackers. Importantly, the attackers could then propagate their malicious DNS settings to all users on the local network, and from that point forward intercept any OAuth authentication tokens transmitted by those users.

DNS hijacking through router compromise. Image: Microsoft.

Because those tokens are typically transmitted only after the user has successfully logged in and gone through multi-factor authentication, the attackers could gain direct access to victim accounts without ever having to phish each user’s credentials and/or one-time codes.

“Everyone is looking for some sophisticated malware to drop something on your mobile devices or something,” English said. “These guys didn’t use malware. They did this in an old-school, graybeard way that isn’t really sexy but it gets the job done.”

Microsoft refers to the Forest Blizzard activity as using DNS hijacking “to support post-compromise adversary-in-the-middle (AiTM) attacks on Transport Layer Security (TLS) connections against Microsoft Outlook on the web domains.” The software giant said while targeting SOHO devices isn’t a new tactic, this is the first time Microsoft has seen Forest Blizzard using “DNS hijacking at scale to support AiTM of TLS connections after exploiting edge devices.”

Black Lotus Labs engineer Danny Adamitis said it will be interesting to see how Forest Blizzard reacts to today’s flurry of attention to their espionage operation, noting that the group immediately switched up its tactics in response to a similar NCSC report (PDF) in August 2025. At the time, Forest Blizzard was using malware to control a far more targeted and smaller group of compromised routers. But Adamitis said the day after the NCSC report, the group quickly ditched the malware approach in favor of mass-altering the DNS settings on thousands of vulnerable routers.

“Before the last NCSC report came out they used this capability in very limited instances,” Adamitis told KrebsOnSecurity. “After the report was released they implemented the capability in a more systemic fashion and used it to target everything that was vulnerable.”

TP-Link was among the router makers facing a complete ban in the United States. But on March 23, the U.S. Federal Communications Commission (FCC) took a much broader approach, announcing it would no longer certify consumer-grade Internet routers that are produced outside of the United States.

The FCC warned that foreign-made routers had become an untenable national security threat, and that poorly-secured routers present “a severe cybersecurity risk that could be leveraged to immediately and severely disrupt U.S. critical infrastructure and directly harm U.S. persons.”

Experts have countered that few new consumer-grade routers would be available for purchase under this new FCC policy (besides maybe Musk’s Starlink satellite Internet routers, which are produced in Texas). The FCC says router makers can apply for a special “conditional approval” from the Department of War or Department of Homeland Security, and that the new policy does not affect any previously-purchased consumer-grade routers.

According to a new law, the Hong Kong police can demand that you reveal the encryption keys protecting your computer, phone, hard drives, etc.—even if you are just transiting the airport.

In a security alert dated March 26, the U.S. Consulate General said that, on March 23, 2026, Hong Kong authorities changed the rules governing enforcement of the National Security Law. Under the revised framework, police can require individuals to provide passwords or other assistance to access personal electronic devices, including cellphones and laptops.

...

Mike Masnick points out that the recent New Mexico court ruling against Meta has some bad implications for end-to-end encryption, and security in general:

If the “design choices create liability” framework seems worrying in the abstract, the New Mexico case provides a concrete example of where it leads in practice.

One of the key pieces of evidence the New Mexico attorney general used against Meta was the company’s 2023 decision to add end-to-end encryption to Facebook Messenger. The argument went like this: predators used Messenger to groom minors and exchange child sexual abuse material. By encrypting those messages, Meta made it harder for law enforcement to access evidence of those crimes. Therefore, the encryption was a design choice that enabled harm...

Google says that it will fully transition to post-quantum cryptography by 2029. I think this is a good move, not because I think we will have a useful quantum computer anywhere near that year, but because crypto-agility is always a good thing.

Slashdot thread.

An elusive hacker who went by the handle “UNKN” and ran the early Russian ransomware groups GandCrab and REvil now has a name and a face. Authorities in Germany say 31-year-old Russian Daniil Maksimovich Shchukin headed both cybercrime gangs and helped carry out at least 130 acts of computer sabotage and extortion against victims across the country between 2019 and 2021.

Shchukin was named as UNKN (a.k.a. UNKNOWN) in an advisory published by the German Federal Criminal Police (the “Bundeskriminalamt” or BKA for short). The BKA said Shchukin and another Russian — 43-year-old Anatoly Sergeevitsch Kravchuk — extorted nearly $2 million euros across two dozen cyberattacks that caused more than 35 million euros in total economic damage.

Daniil Maksimovich SHCHUKIN, a.k.a. UNKN, and Anatoly Sergeevitsch Karvchuk, alleged leaders of the GandCrab and REvil ransomware groups.

Germany’s BKA said Shchukin acted as the head of one of the largest worldwide operating ransomware groups GandCrab and REvil, which pioneered the practice of double extortion — charging victims once for a key needed to unlock hacked systems, and a separate payment in exchange for a promise not to publish stolen data.

Shchukin’s name appeared in a Feb. 2023 filing (PDF) from the U.S. Justice Department seeking the seizure of various cryptocurrency accounts associated with proceeds from the REvil ransomware gang’s activities. The government said the digital wallet tied to Shchukin contained more than $317,000 in ill-gotten cryptocurrency.

The GandCrab ransomware affiliate program first surfaced in January 2018, and paid enterprising hackers huge shares of the profits just for hacking into user accounts at major corporations. The GandCrab team would then try to expand that access, often siphoning vast amounts of sensitive and internal documents in the process. The malware’s curators shipped five major revisions to the GandCrab code, each corresponding with sneaky new features and bug fixes aimed at thwarting the efforts of computer security firms to stymie the spread of the malware.

On May 31, 2019, the GandCrab team announced the group was shutting down after extorting more than $2 billion from victims. “We are a living proof that you can do evil and get off scot-free,” GandCrab’s farewell address famously quipped. “We have proved that one can make a lifetime of money in one year. We have proved that you can become number one by general admission, not in your own conceit.”

The REvil ransomware affiliate program materialized around the same as GandCrab’s demise, fronted by a user named UNKNOWN who announced on a Russian cybercrime forum that he’d deposited $1 million in the forum’s escrow to show he meant business. By this time, many cybersecurity experts had concluded REvil was little more than a reorganization of GandCrab.

UNKNOWN also gave an interview to Dmitry Smilyanets, a former malicious hacker hired by Recorded Future, wherein UNKNOWN described a rags-to-riches tale unencumbered by ethics and morals.

“As a child, I scrounged through the trash heaps and smoked cigarette butts,” UNKNOWN told Recorded Future. “I walked 10 km one way to the school. I wore the same clothes for six months. In my youth, in a communal apartment, I didn’t eat for two or even three days. Now I am a millionaire.”

As described in The Ransomware Hunting Team by Renee Dudley and Daniel Golden, UNKNOWN and REvil reinvested significant earnings into improving their success and mirroring practices of legitimate businesses. The authors wrote:

“Just as a real-world manufacturer might hire other companies to handle logistics or web design, ransomware developers increasingly outsourced tasks beyond their purview, focusing instead on improving the quality of their ransomware. The higher quality ransomware—which, in many cases, the Hunting Team could not break—resulted in more and higher pay-outs from victims. The monumental payments enabled gangs to reinvest in their enterprises. They hired more specialists, and their success accelerated.”

“Criminals raced to join the booming ransomware economy. Underworld ancillary service providers sprouted or pivoted from other criminal work to meet developers’ demand for customized support. Partnering with gangs like GandCrab, ‘cryptor’ providers ensured ransomware could not be detected by standard anti-malware scanners. ‘Initial access brokerages’ specialized in stealing credentials and finding vulnerabilities in target networks, selling that access to ransomware operators and affiliates. Bitcoin “tumblers” offered discounts to gangs that used them as a preferred vendor for laundering ransom payments. Some contractors were open to working with any gang, while others entered exclusive partnerships.”

REvil would evolve into a feared “big-game-hunting” machine capable of extracting hefty extortion payments from victims, largely going after organizations with more than $100 million in annual revenues and fat new cyber insurance policies that were known to pay out.

Over the July 4, 2021 weekend in the United States, REvil hacked into and extorted Kaseya, a company that handled IT operations for more than 1,500 businesses, nonprofits and government agencies. The FBI would later announce they’d infiltrated the ransomware group’s servers prior to the Kaseya hack but couldn’t tip their hand at the time. REvil never recovered from that core compromise, or from the FBI’s release of a free decryption key for REvil victims who couldn’t or didn’t pay.

Shchukin is from Krasnodar, Russia and is thought to reside there, the BKA said.

“Based on the investigations so far, it is assumed that the wanted person is abroad, presumably in Russia,” the BKA advised. “Travel behaviour cannot be ruled out.”

There is little that connects Shchukin to UNKNOWN’s various accounts on the Russian crime forums. But a review of the Russian crime forums indexed by the cyber intelligence firm Intel 471 shows there is plenty connecting Shchukin to a hacker identity called “Ger0in” who operated large botnets and sold “installs” — allowing other cybercriminals to rapidly deploy malware of their choice to thousands of PCs in one go. However, Ger0in was only active between 2010 and 2011, well before UNKNOWN’s appearance as the REvil front man.

A review of the mugshots released by the BKA at the image comparison site Pimeyes found a match on this birthday celebration from 2023, which features a young man named Daniel wearing the same fancy watch as in the BKA photos.

Images from Daniil Shchukin’s birthday party celebration in Krasnodar in 2023.

Update, April 6, 12:06 p.m. ET: A reader forwarded this English-dubbed audio recording from the a ccc.de (37C3) conference talk in Germany from 2023 that previously outed Shchukin as the REvil leader (Shchuckin is mentioned at around 24:25).

Here’s a fossil of a 150-million year old fish that choked to death on a belemnite rostrum: the hard, internal shell of an extinct, squid-like animal.

Original paper.

As usual, you can also use this squid post to talk about the security stories in the news that I haven’t covered.

Blog moderation policy.