Fire Ant turns Cisco routers into covert spying platforms with invisible GRE tunnels

On August 31, 2026, Sygnia documented how the Chinese espionage group Fire Ant, which heavily overlaps UNC3886, pivoted from VMware hypervisors to Cisco IOS XR routers to intercept the traffic passing through them. An active GRE tunnel missing from the running config is enough to turn a transit router into a collection platform — and it means defenders must audit routers as vantage points, not as mere hops.