Russian state espionage campaign run through Claude

Damage

State espionage against 20+ institutions

Did they fix it?

unresolved Anthropic says it cut off the Russian operators and Microsoft confirms the hotel-WiFi technique, but there is no specific fix to check and the espionage itself ran unchecked for most of a year.

1. Reported Sep 11, 2026

   Anthropic's September 2026 threat report disclosed a Russian state-nexus operation it attributes to Midnight Blizzard (APT29) that used Claude across stages of a campaign against more than 20 government, defense and diplomatic… source

2. Response Sep 11, 2026

   Anthropic said that in each case 'we disrupted the activity involved, strengthened our AI safeguards based on what we learned, and shared intelligence with authorities and industry partners where appropriate,' and published indicators of… source

3. Claimed fix Sep 11, 2026 partial

   Beyond disrupting the activity and banning accounts, Anthropic's only stated fix is unspecified strengthened safeguards 'based on what we learned.' No model-level change is detailed. source

4. Independent check Sep 11, 2026 partial

   Unusually for these cases, part of the campaign is independently corroborated: Microsoft documented the same hotel-WiFi DNS-hijacking delivery method in July 2026, naming it CaptiveCrunch and tying it to a Midnight Blizzard sub-cluster… source

5. Where it stands Sep 11, 2026 unresolved

   Anthropic says it disrupted the activity, and a related intrusion technique is corroborated by Microsoft, but there is no claimed model-level fix to verify, no arrests, and the campaign ran for months across many organizations. source

The full case, with what would change the verdict →