Washington and London today jointly accused the Russian government of maliciously targeting global internet equipment for political and economic espionage.

The two governments said the Russian operations, which allegedly involve planting malware on internet routers and other equipment, could also lay the foundation for future offensive cyberattacks.

A joint statement by the U.S. Department of Homeland Security, the FBI and the U.K.’s National Cyber Security Centre said the main targets include “government and private-sector organizations,” as well as providers of “critical infrastructure” and internet service providers.

“Victims were identified through a coordinated series of actions between U.S. and international partners,” according to a companion technical alert issued by the U.S. Computer Emergency Response Team. Both nations have “high confidence” in the finding of Russian-sponsored cyber-meddling, which the alert said has been reported by multiple sources since 2015.

Australia also admonished Russia and accused Kremlin-backed hackers of cyberattacks on hundreds of Australian companies last year.

Respected U.S. cybersecurity researcher Jake Williams said it was difficult for him to understand the motivation for Monday’s alert given that “the activity has been ongoing for some time.”

“Calling the Russians out on this hardly makes much sense unless there’s some other agenda (most likely political),” Williams, the president of Rendition Infosec, added via text message.

Routers direct data traffic across the internet. US-CERT said the compromised routers can be exploited for “man-in-the-middle” spoofing attacks, in which communications are intercepted by a seemingly trusted device that has actually been infiltrated by an attacker.

“The current state of U.S. network devices — coupled with a Russian government campaign to exploit these devices — threatens the safety, security, and economic well-being of the United States,” the alert stated. An email message seeking comment from the Russian embassy in Washington, D.C., received no response.

US-CERT urged affected companies, and public sector organizations and even people who use routers in home offices to take action to harden poorly-secured devices. But its alert cited only one specific product: Cisco’s Smart Install software.

Australian Defense Minister Marise Payne told reporterse about 400 Australian companies were targeted in the Russian attacks, but there was no “exploitation of significance.” The country’s cyber security minister, Angus Taylor, said. “This attempt by Russia is a sharp reminder that Australian businesses and individuals are constantly targeted by malicious state and non-state actors.”

On March 15, US-CERT issued a similar alert saying the FBI and DHS had determined that Russian government “cyber actors” had sought to infiltrate U.S. agencies as well as “organizations in the energy, nuclear, commercial facilities, water, aviation, and critical manufacturing sectors.” It said Russian agents had obtained “remote access” to energy sector networks and obtained information on industrial control systems.

Experts have stressed that the March 15 bulletin did not mean Russia had obtained access to systems that control critical infrastructure such as the power grid. But Russia does have history in this regard, as many security experts blame it for several cyber-sabotage attacks on Ukraine’s power grid.