PHILADELPHIA (CBSNewYork/AP) —  The FBI has confirmed that agents are investigating a cyberattack involving the Democratic National Committee that resulted in the release this weekend in embarrassing emails.

In a statement Monday, the FBI said it was investigating a “cyber intrusion” affecting the DNC and was “working to determine the nature and scope of the matter.”

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“A compromise of this nature is something we take very seriously and the FBI will continue to investigate and hold accountable those who pose a threat in cyberspace,” the agency said in a statement.

Emails arising from the hack were posted over the weekend to WikiLeaks suggesting the DNC favored Clinton over Bernie Sanders during the primary, despite pledging neutrality.

A cybersecurity firm that looked into the DNC breach found traces of at least two sophisticated hacking groups on the Democrats’ network, both of which have ties to the Russian government.

“Other experts are now saying that the Russians are releasing these emails for the purpose of actually helping Donald Trump,” Clinton’s campaign manager Robby Mook said.

Trump brushed off claims that Russia is trying to help his campaign, saying in a Tweet Monday that reports of Russia releasing the emails because Russian President Vladimir Putin likes him is “the new joke in town.”

The release of the emails led to party chief Debbie Wasserman Schultz to announce her resignation.  In a statement, Wasserman Schultz said she will step down at the end of the four-day convention.

Monday morning, she was heckled and booed by members of her own delegation at a DNC breakfast in Philadelphia.

(TM and © Copyright 2016 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2016 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)