Investors have not given up on Wells Fargo & Co. — its stock advanced in 2017 — and its sprawling national footprint and diverse array of business lines continue to produce profits.

But fallout from a fraudulent sales scandal continues to inflict reputational damage and attract regulatory and public scrutiny. And investors are wary about what additional problems may lie ahead for the San Francisco-based banking giant in 2018.

"This is a company with a lot of strengths," Gary Townsend, a Wells investor and GBT Capital Management founder, said in a December interview. "But this has dragged on for a long, long time. And you have to wonder what else will come up, and what else will have to be fixed, and what else will make this drag on for who knows how long into next year."

In September 2016, regulators fined Wells after discovering that employees opened some 2 million fake accounts in existing customers' names to meet lofty sales goals. Internal examinations have since found more than a million additional potentially phony account openings, along with invalid charges and billings to certain auto loan and mortgage customers, among other problems.

Heightened regulatory oversight is all but sure to carry into 2018, Townsend said, noting that the Office of the Comptroller of the Currency in November reportedly cautioned Wells that it could face a formal enforcement action over the auto-insurance and mortgage troubles. That would boost the likelihood of regulators unearthing more problems next year.

And more customers continue to allege wrongdoing, while a wide range of others have either avoided Wells or sought to detach themselves from the bank.

Wells Fargo President and CEO Timothy Sloan

The Navajo Nation, for example, sued Wells in December, alleging that it had targeted members of the Native American tribe who lacked English language skills or who were not familiar with banking services, and then pressured them to open multiple accounts they did not need.

Also in December, Los Angeles lawmakers voted to gauge banks' social responsibility — with punitive action by regulators serving as a key measure — before the city decides which companies will handle its banking business. That could affect Wells' ability to renew a multimillion-dollar deal with the city.

For the third quarter of this year, Wells said revenue and net income were both down from the previous quarter and down from a year earlier, reflecting in part its inability to attract new customers at a level that it had prior to the sales scandal.

Over the past year, Wells President and CEO Timothy Sloan has fired managers tied to wrongdoing, retooled how the bank motivates its employees, and vowed to refund unwarranted expenses linked to sham accounts.

Speaking at a conference in December, Sloan also said business activity with existing customers is building in the fourth quarter and that the company is optimistic about its prospects heading into 2018.

The "feedback that we're getting from our customers in terms of looking at customer activity on the consumer and the commercial side is that … it seems as if that there's some reasonable momentum," Sloan said.

He also touted a wide range of new products and services driven by investments in technology that Wells rolled out in 2017. The efforts are to continue next year and are aimed at deepening ties with customers and adding new ones.

Wells also is focused on employee retention and burnishing its public image broadly.

In late December, for instance, it announced a plan to raise its minimum hourly wage to $15 from $13.50. The change was linked to federal lawmakers' move to cut the corporate tax rate, and many banks made similar announcements. The tax change will bolster the bottom line for many banks, and some observers viewed the announcement from Wells as an effort to ingratiate the bank with not just employees but the government and the public generally.

"They need to rebrand somehow," Mike Matousek, head trader at U.S. Global Investors Inc. and a long-time Wells observer, said in an interview.

But first, Matousek said, investors and customers want to know that Wells has rooted out all major problems with its tarnished service culture. "It's like a dog with fleas," he said. "There is never just one or 20 fleas. There's whole crop of them, and they just keeping popping up until you treat and clean everything from head to toe. Wells Fargo has to cover everything before people are going to really look at it differently."