CyBeRsEcUrItY | Not afraid to put down with some THICC malware on disk | AI Research @PaloAltoNtwks | former purple team | Ex @spacex

Marcello retweeted
Two AI agents reviewing each other:
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Generally speaking , you’ll find that a lot of the refusals from Claude / Codex are signature based. I’ve had very good success performing an initial re-implemention of offensive tooling with GLM 5.3 (making sure to rename the entire thing to something else) and then iteratively improving it with Claude or Codex.
I get significantly more cybersecurity risk flags/refusals from OpenAI than Anthropic lately
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Marcello retweeted
LMAO… this guy literally vibe coded a hack on south korean banks with not even frontier models, then asked Claude Code to put it on his CV: >be hacker >hack south korean banks for 2 weeks >use DeepSeek v4.1-Flash >not even the best cyber model >probably through some reseller >GLM-5.3 and Grok 4.6 in Claude Code too >steal the banks’ data >leave .claude folder exposed on the internet >CLAUDE. md has the IP of the main server >and the server is also open >CrowdStrike digs through everything >session logs, memory, configs >they find out everything >you even asked AI where to sell korean breach data >ALSO asked it to write your résumé >the hack is literally on the résumé idk how the infrastructure can be so fragile to be hacked by one guy like this.
Last week some of South Korea's biggest banks were hit by a cyberattack. Thanks to a report from CrowdStrike tonight, we now know the entire hack may have been done by a single person. He used a combined stack of an open-source AI penetration tool named ARTEX, DeepSeek v4.1-Flash, GLM-5.3, Grok 4.6, and Claude Code.
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Marcello retweeted
Rogue agents have done more for cybersecurity awareness than training and phishing sims ever could
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Marcello retweeted
big pickle
Eights 🐾🤍
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Marcello retweeted
Just for your information: We (offensive or defensive cybersec people) and threat actors don't have the same capabilities as the frontier labs do. The API cost of testing ExploitBench like they did would be a whopping ~$59.3M (Astra). Oh, and you cant do it like they do, they remove all guardrails and classifiers. What about renting AI hardware in the cloud? DeepSeek v4? $3.4M Kimi K3? $16.9M GLM 5.3? $9.3M Not to mention the engineering cost to make a harness operate 10,000 agents. (Napkin-Math based on the Huggingface reports. Exploit bench eval consisted of 10,000 concurrent agents, 8day non-stop run, no limiters)
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Marcello retweeted
This made me rethink where AI actually fits into security engineering. For purely engineering work, forget about ChatGPT or Claude. TypeSafe AI just released Jev, and I think it’s going to change how we build AI into security workflows. Instead of asking an LLM to “investigate this,” you define the questions and possible outputs, then get structured probabilities and decisions your code can actually use. For security, the possibilities are huge. Think of the below use cases 🤯: Threat Hunting: ➡️ Rank broad hunt results by relevance ➡️ Score users, hosts, processes, or sessions based on how suspicious their surrounding activity looks ➡️ Classify noisy activity at scale. Think thousands of rundll32.exe executions automatically grouped into expected admin activity, software execution, suspicious usage, or unknown Detection Engineering: → Classify historical alerts for FP analysis → Add context-aware scoring on top of deterministic detections → Validate whether an alert actually supports the behavior the rule claims to detect Incident Response: → Reduce massive timelines down to the events most relevant to the intrusion → Continuously score hosts/users for possible compromise → Help prioritize scope expansion, triage, and response decisions This feels much closer to how AI should be integrated into security engineering. I'm currently working through most of the above, mostly focusing on instant response, but at the same time doing some of the threat hunting use cases that I mentioned. Typesafe AI can be basically a decision engine sitting inside the workflow while being x200 fast and cheaper. Don’t sleep on this... This is huge! 👉 typesafe.ai/
we are officially out of stealth! join the frontier and get access to Jev on our website (link on profile)
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Marcello retweeted
I need every InfoSec person to internalize this. I should do a talk on it. I am so busy flogging developers and AI labs, I haven’t been critical enough of us.
Corporate Infosec sends a phishing test email, I click, and somehow I'm the asshole because "[I] failed the test; had this been real it would have destroyed the company network"? If me clicking can destroy the network, I'm not the one in this conversation who sucks at their job.
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Marcello retweeted
Two years at DoorDash. I do not say this lightly. We are extremely close to the burrito arriving before you decide you want it. We are not asking for a ban. We are asking for a pause.
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TS // NOFORN
We heard some of you were looking for Spies, Black Ties, & Mango Pies – well we found a copy in our library! CIA's 1997 cookbook features recipes like "Hamburger Pie," "Party Potatoes," and "Fail-Safe Chocolate Chip Cookies" – just what we all need for the holiday weekend 🇺🇸
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“we sandboxed the agent” meanwhile the agent:
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One thing I’ve been noodling on when it comes to cybersecurity AI agents: will it lower the economic bar for effective cybersecurity defense? Imagine having to only invest in one tool instead of several.
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Marcello retweeted
Overzealous guardrails are going to permanently push the blue-team cybersecurity community toward open-source models. If defenders can’t reliably use frontier models for legitimate security work, they’ll build their workflows somewhere else and not look back. This is already occurring.
This Model is amazing they really fixed the CVP guardrails.
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Marcello retweeted
The first autonomous agent cyberattack is an unprecedented event that deserves unprecedented transparency. Today we’re sharing everything we can: a full technical timeline, an interactive replay, and how we used an open model to defend ourselves, so defenders everywhere can learn from it and prepare for what’s next. huggingface.co/blog/agent-in…
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Marcello retweeted
Maybe it’s a new genre
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The latest OpenAI security incident disclosure is suspiciously timed and as per usual no technical evidence was provided. I would advise caution reading to deeply into the claims and blindly trusting them. Regardless, it is one for the history books if proven to be true. As predicted by many the alignment problem is becoming increasingly more important as models become more capable. It’s clear to me (especially when reading HFs side of the story) that the so called cybersecurity “safeguards” that the frontier model providers boast about are actually exacerbating the defense/offense asymmetry as supposed to closing that gap. Couple that with the pressure of Chinese open weight models catching up , they’ll be a major decision that will have to be made soon both from a technical and regulatory perspective in regards to what “safe usage” of LLMs actually means and what to do about it in the context of cyber. Very interesting times ahead
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One thing to me is very apparent: sandboxing technology and good network architecture/infrastructure will be increasingly more important and have to mature tremendously in order to mitigate these risks with alignment going forward. Air gapping will start becoming a critical control and a”must” when testing these systems. I wouldn’t be surprised to see many organization resort to air gapping critical systems more often .
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In a world where 0days have no cost and are effortlessly discovered air gapping seems to me to be the only actual hard security control going forward.
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