At least one Trump staff member’s email account was infected with malware in 2015 and sent malicious emails to colleagues, according to one insider for the Republican candidate’s campaign and an outside security expert. It was unclear whether or not the hackers actually gained access to campaign computers…

The Trump campaign has hired security firm CrowdStrike, which also is assisting the Democratic National Committee, according to one person briefed on the matter. The company declined to comment.A different outside security firm was hired to examine software the Trump and Clinton campaigns use to manage mailings, electronic outreach and other campaign efforts, another person who was briefed on the issue said.A spokeswoman for Trump’s campaign declined to comment. A spokesman for the Republican National Committee could not immediately be reached for comment.

The tools and techniques used to hack Republican targets resemble those employed in attacks on Democratic Party organizations, including the DNC and Clinton’s campaign organization, two sources said. That has led U.S. officials to reach a preliminary assessment that Russia’s military and civilian intelligence agencies or their proxies have targeted both political parties.