In a speech in swing state Ohio, she accused the U.S. bank of "bullying thousands of employees into committing fraud" as they tried to meet sales goals. She called Wells Fargo's fake account opening practices, which prompted a $190 million settlement with U.S. regulators and congressional grilling for CEO John Stumpf, "really shocking."
"It is outrageous that eight years after a cowboy culture on Wall Street wrecked our economy we are still seeing powerful bankers playing fast and loose with the law," she said.
In his testimony last week, Stumpf apologized for the millions of accounts opened without customer approval but denied that an "orchestrated effort" to defraud customers took place. The bank fired 5,300 people, or less than 2 percent of its workforce, in relation to the sales practices over five years.
Wells Fargo stressed to CNBC that it eliminated sales goals for its retail banking team effective at the start of the month. The bank said it strives to make employees "feel valued, rewarded and recognized and we pride ourselves on creating a positive environment for our team members, including market competitive compensation."
During her speech, Clinton targeted not only Wall Street but also pharmaceutical companies and Donald Trump, her Republican rival for president. She highlighted plans to empower the Consumer Financial Protection Bureau, which discovered Wells Fargo's practices, close tax loopholes on wealthy Americans and businesses and penalize pharmaceutical companies that significantly hike drug prices.
Clinton in particular seized on Trump's 1995 tax return, which The New York Times published over the weekend amid Trump's refusal to release his returns like most recent presidential candidates. The record showed that Trump reported a net loss of more than $900 billion amid a string of failed ventures, which could potentially shield up to 18 years of personal income from taxes.
Clinton contended that Trump seemed to be "contributing nothing to our nation" by minimizing his tax burden. Trump has justified his tax record by saying he can fix the U.S. tax system because he knows its flaws.
Trump advisor and former New York Mayor Rudy Giuliani called Trump a "genius" for reducing his taxes, a claim which Clinton disputed.
Clinton asked: "What kind of genius loses a billion dollars in a single year?"