Russia is using compromised computer-network equipment to attackU.S. and British companies and government agencies, the twocountries warned in an unprecedented joint alert.

The warning on Monday came from the U.S. Department of HomelandSecurity and Federal Bureau of Investigation and Britain's NationalCyber Security Center. It included advice to companies abouthow to protect themselves and warnedspecifically of attacks on routers, the devices that channel dataaround a network.

“Russian state-sponsored actors are using compromised routers toconduct spoofing 'man-in-the-middle' attacks to support espionage,extract intellectual property, maintain persistent access to victimnetworks and potentially lay a foundation for future offensiveoperations,” according to a joint statement. “Multiple sourcesincluding private and public-sector cybersecurity researchorganizations and allies have reported this activity to the U.S.and U.K. governments.”

The main advice offered Monday for individuals and companies:Make sure that your router software is up-to-date and its passwordis secure.

“Once you own the router, you own the traffic,” Jeanette Manfra,assistant secretary at the Department of Homeland Security, toldreporters on a joint conference call.
U.S. and U.K. relations with Vladimir Putin's administration are ata low point, following the alleged use of nerve agent to poison aformer double agent in Britain in March and the U.S.-led bombing ofSyria over the weekend after the Russian ally's alleged use ofchemical weapons on civilians. Britain's GCHQ intelligence agencyhad already warned that Russia was using its cyber capabilities totarget democracies.

The Pentagon has said Russian “trolling” activity increased2,000 percent after the Syria strike.

While the officials were reluctant to give precise details ofthe threat, they said once a router had been hacked, it could beused not simply to capture data traveling through it, but also tocarry out attacks on other computers, potentially overwhelming theInternet's communications infrastructure.

“It's a tremendous weapon in the hands of an adversary,” HowardMarshall, a deputy assistant director of the FBI, said.

Such attacks, where computers are bombarded with requests fromother computers that have already been hacked until they crash, area well-known weapon in cyberwarfare.

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