"They promised to take on corruption. Remember that?" Obama said while going after Trump and Republicans during a Democratic campaign event in Milwaukee.
"They have gone to Washington and just plundered away. In Washington, they have racked up enough indictments to field a football team," he said.
"Nobody in my administration got indicted."
As of this month, Mueller's team has indicted or secured guilty pleas from 32 people as part of his sprawling probe into Russian meddling in the 2016 election.
Four of those people include former Trump campaign adviser George Papadopoulos, former Trump campaign chairman Paul Manafort, former Trump campaign aide Richard Gates and Trump's former national security adviser, Michael Flynn.
Trump has repeatedly slammed the investigation as a partisan "witch hunt" and called for it to be ended.
"They didn't care about emails," Obama said. "And you know how you know? Because if they did, they'd be up in arms right now as the Chinese are listening to the president's iPhone that he leaves in his golf cart. It turns out, I guess it wasn't that important.”