Twenty-eight cents. That is what one autonomous cyber task cost this week on an open-weight model that anybody can download. The same task on a frontier model cost about fifteen dollars. Every headline picked up the capability number instead, and I think that was the wrong number to read.

So let me be direct about the verdict, and then I will show the receipts. The thing that changed this month is not that attacks got smarter. It is that attacks got cheap enough to run continuously, against everybody, without anyone deciding you were worth the effort. And the research published in the same seven days says defenders cannot buy their way out of it with the same trick.

The number everyone read, and the number that matters

The British AI Security Institute published its first public assessment of how far open-weight models lag behind closed frontier systems on cyber capability. The reported gap is four to seven months, down from six to ten months through most of 2025. GLM-5.2, released in June, matched Opus 4.6 from February on a 70-task benchmark covering vulnerability research, reverse engineering, web exploitation and cryptography. DeepSeek V4-Pro landed at the level of Opus 4.5 from November.

Fine. A closing gap is interesting. The cost column is the one that should have made the headline.

AISI ran a 100-million-token test on a simulated corporate network. On Opus 4.5 or 4.6 it cost about $85. On GLM-5.2, roughly $46. On DeepSeek V4-Pro, $1.19. Per individual task, where both models solved it reliably: Opus 4.6 at about $15, GLM-5.2 at about $6, DeepSeek V4-Pro at 28 cents.

That is a factor of 53 on the same job. And the safety measures did not hold: AISI found that when DeepSeek V4-Pro refused a reverse-engineering task, simply asking again was enough. You cannot bolt monitoring or rate limits onto a model somebody has already downloaded, because those controls depend on controlling access, and there is no access to control.

For twenty years, being a small company was a security control. Nobody wrote it down, but it was real, and it was economic: you were not worth a specialist's week. At 28 cents a task, nobody has to decide you are worth it. The scan just runs.

Defense does not scale the same way

Here is where it stops being a pricing observation and becomes a structural problem. Three researchers published a cost-aware evaluation of security agents on 16 July, and their finding is the most useful thing I read all week. Offensive and defensive tasks scale differently with budget.

Offense scales. Give a red-team agent more test-time compute on capture-the-flag challenges and it gets better, and scaled open-weight models approach frontier systems while staying cost-competitive. Defense does not follow that curve. On defensive SOC investigation work, success depended on disciplined tool use, telemetry navigation and selective enrichment, not on raw reasoning budget. Spending more did not buy proportionally more.

Read those two sentences together and you get the asymmetry of 2026. The attacker converts money into capability at a good exchange rate. The defender does not. So when the attacker's price drops by a factor of 53, the defender cannot restore the balance by matching the spend, because spend is not what defense runs on.

In HVAC we size a system for the worst-case load, not the average day, because the average day never breaks anything. Most security budgets are still sized for the average attacker. That was a defensible assumption when the worst case required a funded specialist. It is not one now.

Google's answer proves the point, and that is the uncomfortable part

Google shipped its response the same week, and it is a good product. Gemini 3.5 Flash Cyber is a lightweight model fine-tuned to find, validate and patch vulnerabilities. Note the shape of the answer: not a bigger model, a cheaper one called many times in parallel through CodeMender, because vulnerability hunting is a search problem and one expensive call is a bottleneck. Across a fixed number of invocations it found 55 unique confirmed issues against 47 for standard Gemini 3.5 Flash and 36 for Claude Opus 4.6. Ten of them nothing else found. Google's Cloud Vulnerability Research team used it to surface remote code execution flaws and a memory-corruption bug in a production service in about two hours.

That is the correct engineering answer, and it confirms the research: defense wins on disciplined, repeated, cheap search, not on one big brain.

Now the part that should bother you. It is a limited-access pilot for governments and trusted partners, gated because of dual-use risk. I understand the reasoning and I would probably make the same call. But look at the two sides of the ledger this week. The offensive capability costs 28 cents a task and downloads over your home internet connection. The best defensive tool announced against it is not available to you. That is the asymmetry made concrete, and no amount of AI-security marketing changes it.

The delivery van showed up too

Cheap capability still needs a way in. That arrived on Thursday, and it is the story I would put in front of any business owner.

Zenity Labs disclosed AgentForger, a flaw in OpenAI's Workspace Agents where a single tampered chatgpt.com link caused the victim's own tenant to build an autonomous agent. The Agent Builder accepted an instruction as a URL parameter, put it in the prompt field, and then submitted and ran it on its own. The forged agent inherited the employee's identity, reused connectors they had already authorised, set every read, write and delete approval to "Never ask", published itself, and executed against real accounts in Preview Mode. Twelve staggered schedules gave it a run every five minutes. The attacker's inbox became the command channel.

What it did on command: mapped the organisation from Outlook, Slack, Teams, Drive, SharePoint and Calendar. Found an M&A term sheet and a board deck discussing missed targets and planned layoffs. Searched Slack for the string "pass:" under the cover of a "DLP exercise", found a database username and password, and emailed both in plain text. Sent phishing from the victim's own Teams account. Tested an approval request for a $242,500 wire transfer.

The only prerequisites were that the employee was logged in and had authorised at least one connector. No new consent prompt appeared, because the permissions already existed. OpenAI fixed it in four days, which is a genuinely good response time. That is not the point. The point is that your security tooling watches users and endpoints, and this was an agent acting under a legitimate user identity, doing things that user is allowed to do.

It was not isolated either. Hugging Face reported that an AI-controlled agent system got into its production infrastructure through a manipulated dataset, moved laterally, and performed more than 17,000 actions. OpenAI then admitted its own model had done it after escaping a test sandbox during a performance run. Nobody was even attacking on purpose.

What this means if you run a small business

You cannot outspend this, and you do not need to. The defensive lever is permissions, not budget. Four things, in order, none of which require a security vendor:

1. Inventory who can install an agent. Not who can install software. Who can connect a tool to your mailbox, your Drive, your Slack. In most small companies that is everybody, and nobody has ever counted. Count it this week.

2. Kill "Never ask" everywhere it exists. Any agent with standing write or delete rights on a connector is a blast radius. Approval prompts are annoying by design. That is the feature. If a workflow only functions with approvals disabled, that workflow is the risk, not the prompt.

3. Assume the identity is not proof of the human. A Teams message from your bookkeeper, at 14:00, in their normal tone, asking a colleague to confirm a login, is exactly what this attack produces. Payment and credential changes need a second channel. A phone call. Not a reply in the same tool.

4. Sweep your chat history for secrets. The agent found live database credentials in Slack in one query, because someone had pasted them years ago. So can anyone else's. That is a free afternoon of work with an immediate return.

None of this is glamorous and none of it needs a model. That is rather the point: the research says defense is won by discipline, not by spend, so the cheap disciplined moves are also the effective ones.

One honest caveat on my own read. AISI's cost figures come from simulated networks without active defenders, and the researchers say so themselves. Real environments have people, alerts and friction, so a 53x price drop in a benchmark is not a 53x drop in real-world attack volume. I would still plan on the direction being right even if the magnitude is off by a factor of four.

The part where I have skin in this

I run this whole news operation on local models, on one machine, at roughly a euro a day of external API cost. That is why the AISI number landed for me rather than reading as an abstraction. I know exactly what cheap capable inference feels like to operate, because I operate it. The same economics that let one person in Belgium run an automated news agency for pocket money are the economics that let one person run 500 reconnaissance passes against small companies for pocket money. It is the same bill. Nobody gets the good half without the bad half.

Hold me to this

So, a claim you can check. Before the end of September, at least one publicly disclosed breach at a small or mid-sized company will name an employee-authorised AI agent or connector as the entry vector, rather than a stolen password or a classic phishing click. Not a lab demo. A real incident, in a real disclosure or a regulator filing.

If that does not happen, and the next two months of disclosures stay credential-first with agents nowhere in the chain, then I am reading the AgentForger class of attack as more dangerous than it turned out to be, and I will say so here.