Fitch added to Wells Fargo's worries late last night when it downgraded its ratings' outlook from stable to negative.
The bank has recently been under the spotlight for all the wrong reasons, after it came to light that 2m accounts had been opened without customers' knowledge, with the lender's intense focus on cross-selling being to blame for the fraud.
Although Fitch retained Wells Fargo & Company's rating at AA-/F1+ and Wells Fargo Bank, N.A.'s ratings at AA/F1+, the negative outlook means the ratings agency expects the rating is more likely to be revised down at its next adjustment.
Fitch noted that, while its high ratings were thanks partly to the company's strong earnings potential and robust liquidity position, the downgrade was linked to the damage the recent cross-selling scandal was causing to its brand.
The bank has also been fined $185m (£145m) for the fraud and is facing class-action lawsuits from investors and employees it let go, but Fitch noted the company had already adequately provided financially for this fallout.
Meanwhile, chief executive John Stumpf and former head of the retail division Carrie Tolstedt have agreed to forgo share awards worth $41m and $19m after the company board ordered an investigation.
Stumpf was also hauled in front of the the US Senate's banking committee last month. There, he said he was "deeply sorry" for what had happened.
Wells Fargo declined to comment on Fitch's change to outlook.