Last week, Anthropic announced it was restricting the initial release of its Mythos Preview model to "a limited group of critical industry partners," giving them time to prepare for a model that it said is "strikingly capable at computer security tasks." Now, the UK government's AI Security Institute (AISI) has published an initial evaluation of the model's cyber-attack capabilities that adds some independent public verification to those Anthropic reports.
AISI's findings show that Mythos isn't significantly different from other recent frontier models when it comes to tests of individual cyber-security related tasks. But Mythos could set itself apart from previous models through its ability to effectively chain these tasks together into the multi-step series of attacks necessary to fully infiltrate some systems.
"The Last Ones" finally falls
AISI has been putting various AI models through specially designed Capture the Flag challenges since early 2023, when GPT-3.5 Turbo struggled to complete any of the group's relatively low-level "Apprentice" tasks. Since then, performance of subsequent models has risen steadily, to the point where Mythos Preview can complete north of 85 percent of those same Apprentice-level CTF tasks.
DW Russian 
