Russian government hackers are believed to be responsible for infiltrating computer systems at multiple U.S. agencies in recent months, including the Pentagon, the Department of Homeland Security and the Department of the Treasury, according to government agencies and media reports. Russia has denied the accusations. The hack hinged on a vulnerability on a software monitoring product from SolarWinds, a company based in Austin, Texas. The company works widely with the federal government and hundreds of large U.S. companies. Many use SolarWinds’ Orion software to monitor their computer networks. SolarWinds has some 300,000 customers, but says “fewer than 18,000” installed the version of its Orion products earlier this year that now appear to have been compromised. So far, the list of affected U.S. government entities includes: The Commerce Department; Department of Homeland Security; the Pentagon; the Treasury Department; the U.S. Postal Service; and the National Institutes of Health.