Anthropic says new defenses cut distillation data harvested from Claude by 90 to 99 percent

Anthropic says it has made serious headway against people trying to copy Claude’s homework. According to the company, new defenses have cut the amount of data harvested through distillation attacks by 90 to 99 percent. The figures come from a September 2026 threat intelligence report. In it, Anthropic details how it has tracked, attributed and disrupted illicit attempts to extract Claude’s capabilities. The focus falls mainly on reasoning, coding and tool use. Nearly 200 million exchanges, one very large customer Technically, a rival collects large volumes of a stronger model’s responses and uses those transcripts as training data. Anthropic says it attributed nearly 200 million distillation-related exchanges across five separate campaigns in its latest report. The biggest of the five stands out. Anthropic linked it to Alibaba’s Qwen, and it involved more than 151 million exchanges between May and July 2026. This is not the first time Anthropic has gone public on the issue. Back in February 2026, the company disclosed earlier campaigns that involved more than 16 million exchanges. Those operations relied on approximately 24,000 fraudulent accounts. How the defenses actually work An...