UPDATE: 7:15 p.m. EDT — House Homeland Security Chairman Mike McCaul said Russian hackers breached the Republican National Committee’s computer systems.

"It’s important to note … that they have hacked not only hacked into the DNC but also into the RNC,” McCaul, R-Texas, told CNN. “So they are not discriminating one party against the others. The Russians have basically hacked into both parties at the national level and that gives us all concern about what their motivations are.”

The RNC strategist Sean Spicer said, however, McCaul is wrong.

Original story:

The Association of State Democratic Chairs is warning Democratic Party officials hackers have breached some of their accounts and impersonated them, further raising fears Russia was attempting to influence the U.S. presidential election.

Politico said it obtained a copy of the warning, which tells recipients to avoid WikiLeaks because of concerns about malware embedded on the site.

“Due to the potential of malware attached to the site, we are under advisement from [interim Democratic National Committee] Chair [Donna] Brazile to stay away in the interest of maintaining some security,” said the email written by Raymond Buckley, president of the Association of State Democratic Chairs, which is affiliated with the DNC.

Brazile issued a similar warning Tuesday.

“We would urge anyone attempting to access these documents to proceed with extreme caution given the potential malware risks,” she said.

Buckley said Monday his Twitter account had been hacked, and Facebook warned him someone impersonating him tried to delete his profile.

The warning comes in the wake of several high-profile hacks. Russian hackers were suspected in attacks on voter registration systems in Illinois and Arizona in June. No damage was caused by the hacks, and it was unclear whether the attack was sponsored by the Russian government or was the work of criminals.

Russia has been blamed for hacking the DNC’s email and releasing messages purporting to show an unfair bias toward Hillary Clinton at the expense of Bernie Sanders. The release came ahead of the Democratic National Convention in July and forced the resignation of Party Chair Debbie Wasserman Schultz.

More emails were released Tuesday and posted to WikiLeaks’ Twitter account.

“There’s one person who stands to benefit from these criminal acts, and that’s [Republican presidential nominee] Donald Trump,” Brazile said, noting Trump’s comments encouraging Russian hacking.

Trump, who has expressed admiration for Russian President Vladimir Putin, suggested Russian hackers try to find Clinton emails that have not made available. He later said he was being sarcastic.

Clinton has accused Russia of trying to interfere in the election.

“If you find a turtle on a fence post, it didn't get there by accident,” she said earlier this month. “I think it’s quite intriguing that this activity has happened around the time Trump became the nominee.”