Microsoft has a new AI cybersecurity model called MAI-Cyber-1-Flash, and when it’s combined with agentic security system MDASH and OpenAI’s GPT-5.4 model, it outscores Anthropic’s Claude Mythos 5 by 12 points on a key benchmark. The security product is designed for “using AI to defend against AI,” Microsoft says.
The combination of MAI-Cyber-1-Flash with MDASH — which launched in May — is called Project Perception, and it enters public preview on Aug. 3, built directly into Microsoft Defender. It will slowly roll out to all Microsoft Security products.
According to benchmarks posted by Microsoft on Monday, the combination scored 96% on CyberGym, compared with Mythos 5 at 84%.
Pricing is consumption-based, measured by the number of security compute units you use. As AI agents run scenarios, they consume SCUs, so the more work performed, the more you pay — but Microsoft says cost savings are almost 50% of the current MDASH configuration on the market now.
Speaking at a Microsoft briefing on Monday morning, Mustafa Suleyman, CEO of Microsoft AI, explained the handover process between MAI-Cyber-1-Flash and GPT-5.4.
“MAI-Cyber-1-Flash handles about 90% of the queries. It detects the vulnerabilities, it patches them, ships them and then proves that it was actually a valid and correct solve. And then it basically defers about 10% of the queries to GPT-5.4, which is obviously a larger model, about 10x larger, and it solves those,” Suleyman said. “In conjunction, as the models hand off between each other, they’re actually not just able to deliver better performance than all of the other models combined — they do so at 50% of the cost.”
Suleyman called the CyberGym benchmark result “quite a remarkable result.”
It follows the launch of Anthropic’s Claude Fable 5 last month, the first publicly available model from the Mythos family. At the time, Anthropic said Mythos was so good at finding cybersecurity flaws that it could break the internet if used unchecked — and Anthropic was forced to walk back the Fable 5 and Mythos 5 launches within days because the US government said it was aware of a way to “jailbreak” the model and bypass limits. When Mythos was first announced, it was released only to select government agencies and tech professionals.
“Microsoft has long been the trusted steward of some of the most valuable, important government and enterprise data in the world over many decades. We’ve accrued a phenomenal amount of data in that time,” Suleyman said Monday. “It’s that data combined with the expertise that we have from the world-class cybersecurity experts in the company that we’ve been able to really drive this combined model.”