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2,900 Sign-Ins a Minute: Microsoft Names a State Actor Behind the ConnectWise Compromise, Driving ARTEX

Agent & Supply Chain Security by al-ice.ai Editorial

Microsoft Security Research and Microsoft Threat Intelligence published a joint report on 21 October 2026 that does something the AI-and-security conversation has needed for months: it attributes a specific, large-scale, agentically-executed intrusion campaign to a named state-aligned actor, and it puts measured numbers on how fast the agents worked. Microsoft assesses that Storm-0940 — a China-state aligned actor it says has been active since 2021, with no known industry aliases — was responsible for the ConnectWise supply chain compromise, and that it used the open-source agentic AI penetration testing framework ARTEX to run it.

For this site, that single sentence welds together two investigations we had been running on separate tracks. We covered the ConnectWise Cloud Backup application-credential compromise on 20 October as an identity and consent-architecture failure, with no attribution available. We covered ARTEX itself on 7 October when South Korean investigators tied it to seven breached financial institutions, and again on 9 October when CrowdStrike reconstructed an operator’s campaign from exposed session logs — an operator who read, in that evidence, as an individual criminal with a résumé to pad, not as a government programme. Microsoft’s report says the same tool is now in state-aligned hands, and explicitly notes it has identified threat actors across multiple geographic regions using the framework. The capability did not stay with its first user, which is the ordinary fate of open-source offensive tooling and the reason the tool’s author pulling it in October changed little.

The numbers, and what they actually measure

Two figures from the report are being quoted everywhere, and they are worth separating because they describe different phases of the campaign and have very different implications.

The first is the one that sounds most alarming and is in fact the failure. Between 10 and 14 October 2026, Storm-0940 infrastructure at 144.172.64[.]99 ran an automated cross-tenant password-spray campaign against 327 accounts across eight organisations. Microsoft telemetry captured more than 151,000 failed logon events, peaking on 11 October at 2,900 failures per minute, with more than 111,000 failures concentrated into a single day. Forty-eight accounts took more than 1,000 failures each, and lockout responses accounted for nearly 98% of all activity. Microsoft is explicit about the outcome: “no successful authentication, token issuance, Graph call, or directory change was observed.” The spray did not work. What it produced was an enormous, unmissable volume of noise — and, read correctly, a free four-day advance warning that the organisations involved were being targeted by something operating at machine speed.

The second figure is the one that mattered. After the ConnectWise application identities were compromised, Storm-0940 used ARTEX to attempt sign-ins to more than 2,250 tenants at 2,900 sign-in attempts per minute. Note what changed between the two phases: not the rate, which is essentially identical, but the credential. Password spraying at 2,900 attempts a minute hits lockout policy and fails 151,000 times. The same automation holding a valid application credential walks straight in, because — as we wrote when the ConnectWise story broke — application sign-ins have no MFA prompt, no user and no device, and every tenant that granted consent pre-authorised the session. Agentic speed is not itself the weapon. It is a multiplier that gets absorbed entirely by a working authentication control and becomes devastating the moment one is bypassed.

Microsoft’s infrastructure link between the two phases is the connective tissue of the attribution, and it is concrete. The password-spray address 144.172.64[.]99 sits in the same 144.172.64.x range reported in the public ConnectWise indicators, and Microsoft says the vendor’s 16 October advisory shared an indicator matching exactly that address. Readers of our earlier piece will recall Huntress’s observed address as 144.172.64[.]128 — a different host in the same /24. Both are accurate; they are different nodes of the same infrastructure, used in different phases. If you are hunting, hunt the range and the behaviour, not the single IP, and Microsoft’s own guidance says as much: do not limit review to the published addresses.

Under three hours from targeting to privileged cloud access

The detail with the longest shelf life is not the ConnectWise incident at all. Microsoft reports that since as early as September 2026, Storm-0940 has used ARTEX to automate attacks against hundreds of organisations globally — naming aerospace and defence, automotive, chemicals, energy, financial services, government, legal, manufacturing, media, military, semiconductor, software, technology, and think tanks and non-profits — and that several of these ARTEX-driven attacks ended with the actor holding privileged access to cloud infrastructure, in multiple instances less than three hours from initial targeting.

Microsoft’s framing of why this matters is the right one and deserves quoting in substance rather than paraphrase: when these activities are automated with AI they generate a large volume of traffic and log data that may well generate alerts — but the speed of the activity leaves very little time for defenders to respond to those alerts and remediate in a coordinated fashion. The company also notes that agents are not constrained by the things that constrain humans: they work around the clock, on weekends and holidays, and attempt multiple breach paths simultaneously.

That is a precise statement of a problem this site has now documented from several directions, and it is a detection-to-response latency problem rather than a detection problem. The alerts fired. Microsoft explicitly says the majority of the targeting was unsuccessful and that lockouts dominated. The actor still achieved privileged cloud persistence at many organisations in a brief window, because the gap between an alert appearing in a queue and a human coordinating a containment decision across a tenant is measured in hours, and the adversary’s loop is now measured in minutes. Compare the economics we reported in the Cairn agent-army campaign — roughly 23 hours and about $50 of tokens per successful intrusion, run by one person against more than 100 companies. Storm-0940 is the state-aligned expression of the same curve.

What ARTEX is, per Microsoft

Microsoft’s technical description of the framework adds detail beyond what was public during the Korean investigation. ARTEX is an open-source penetration testing framework that can use any AI model; it is a multi-agent LLM system written in Go with a Next.js frontend; and while its UI and generated output default to English, it can be switched to Korean, Mandarin, Spanish or Japanese. The agents run an autonomous penetration test from reconnaissance through data exfiltration with little human interaction required, accumulating discovered assets and vulnerabilities into a graph as they go.

Two things follow from “can use any AI model.” First, model-provider safety mitigations are a weak control here by construction — the framework is an orchestration layer, and swapping the backend is a configuration change. Second, the model-side telemetry that made the CrowdStrike reconstruction possible is not guaranteed to exist in any given deployment. Defenders should not plan on the attacker’s choice of backend being observable.

In the ConnectWise campaign specifically, Microsoft says ARTEX accelerated scanning and reconnaissance, password spraying, and OAuth application abuse at downstream victims. The follow-on is the part worth studying: in multiple affected environments, agents operating on the actor’s behalf progressed beyond authentication into Microsoft Graph and directory operations — reconnaissance, application credential modifications to establish persistence, and changes involving identities, groups and privileged roles. Microsoft warns plainly that these credential changes can remain active as a backdoor even after the original compromised application is remediated. That is the same persistence pattern Huntress observed and we flagged last week: a self-granted Global Administrator role and fresh client secrets minted on other trusted applications. Two independent vendors describing the same tradecraft should raise your confidence that it was systematic rather than opportunistic.

Microsoft is also careful about a claim it declines to make, and so are we: the presence of an affected application, or even a successful threat actor authentication, does not necessarily indicate that customer data was accessed or exfiltrated. The report states the activity did not result from a compromise of, or a vulnerability in, Microsoft corporate systems, products or services. No CVE applies to any of this. Nothing here belongs in KEV. The entry point was a vendor-held credential and a consent grant, which is an architecture, not a bug.

What to do

If you have not already acted on the ConnectWise advisory, the immediate guidance in Microsoft’s report is operational and specific. Keep affected ConnectWise application connections disabled until ConnectWise publishes formal restoration instructions. Critically: do not delete the enterprise applications as a first response — preserve configuration and evidence before making irreversible changes, because deletion destroys the record of what the attacker altered. Inventory the application IDs and record the local service-principal Object ID in each tenant, and search by application ID rather than display name, since older tenants may carry SkyKick-era naming.

On timeframe, Microsoft says review activity from at least 15 October 2026, and where records allow, extend service-principal sign-in review back to 1 October. Given that the spray phase ran 10–14 October from the same infrastructure range, the earlier boundary is the one to use if you have the retention. Review successful and failed service-principal sign-ins separately — the failures are where the four-day advance warning lived, and most teams only query the successes.

Then hunt the persistence rather than the intrusion. Audit Microsoft Entra audit records for application or service-principal credential additions; new applications, service principals or owners; app-role assignments and consent grants; privileged role assignments; and changes to users, groups, authentication methods or Conditional Access. Treat any credential you cannot account for as hostile and rotate it. Review Microsoft 365 audit records for directory- and permission-enumeration from unusual addresses, and for unusual mail or file access, downloads, forwarding, inbox or transport rules, and delegated mailbox permissions.

The durable lesson is about response design, not indicators. If a compromised vendor credential plus an agent framework can reach 2,250 tenants in the time it takes to staff an incident bridge, then containment for third-party application identities has to be pre-authorised and ideally automated — a decision made before the incident about who may disable a vendor app at 3am without a meeting. The controls that actually blunted this campaign were boring and preventive: lockout policy absorbed 151,000 attempts and produced zero successes. The controls that failed were the ones that assumed a human would have time to read an alert. Least-privilege consent, expiring application secrets, and a standing inventory of which third-party apps hold which permissions in which tenants are what shrink the blast radius next time, and there will be a next time — Microsoft says the framework is already in use by actors in multiple regions.

Our verification was read-only. The attribution of the ConnectWise supply chain compromise to Storm-0940, the actor’s characterisation as China-state aligned and active since 2021 with no known industry aliases, the September 2026 start of ARTEX use, the targeted-industry list, the “less than 3 hours” targeting-to-privileged-access finding, the 10–14 October password-spray figures (144.172.64[.]99; 327 accounts across eight organisations; 151,000+ failed logons; 2,900 failures per minute peak on 11 October; 111,000+ in a single day; 48 accounts over 1,000 failures; ~98% lockout responses; no successful authentication observed), the “more than 2,250 tenants at 2,900 sign-in attempts per minute” figure, the ARTEX technical description (open-source, model-agnostic, multi-agent, Go with a Next.js frontend, English default with Korean/Mandarin/Spanish/Japanese options, recon-through-exfiltration with asset graphing), the Microsoft Graph and directory follow-on activity, the persistence warning, the statement that no Microsoft system or product was compromised, the 16 October ConnectWise advisory IP match, and all mitigation guidance were read first-hand from the Microsoft Security Blog report of 21 October 2026. The 144.172.64[.]128 address and the Global Administrator self-grant and client-secret persistence detail are from Huntress via SpecterOps as reported in our 20 October briefing, not restated from the Microsoft report. Microsoft’s assessment of responsibility is an attribution by a vendor, and we report it as such rather than as established fact. No tenant was accessed, no indicator was resolved or contacted, no tooling was obtained or executed, and no request was sent beyond reading the cited public pages. Brave Search was used for discovery only.

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