Deutsche Bank is still recovering after being hit with billions in fines back in 2015, its chief executive officer John Cryan told CNBC, after the bank posted another year of losses on Friday morning.

The German lender reported a net loss of 2.2 billion euros ($2.75 billion) in the fourth quarter of 2017 — worse than the net loss of 1.25 billion euros that Reuters analysts had forecast.

For the year, the German bank posted a 497 million euro loss ($621 million), compared to a 290 million euro loss that Reuters analysts had estimated. This was the third consecutive annual loss for Deutsche Bank. The bank's results were impacted by a drop in investment banking as well as tax changes in the U.S.

"We are coming out (of crisis) and were it not for the U.S. tax reform whatever it was 11, 10, 11 days before the end of the year, then we would have been reporting at least a positive result at the bottom line, which psychologically always feels better than a negative result," Cryan said Friday.

He told CNBC that 2015 was the "bottom line" for the bank, when several impairments and other charges contributed to a 6 billion euro net loss.

Deutsche Bank said Friday morning that it had a non-cash charge of about 1.4 billion euros due to a valuation adjustment on its U.S. Deferred Tax Assets. Without that, the bank said it would have made a full-year net income of about 900 million euros.

On the investment banking side, the German bank said that low volatility, reduced client activity and challenging trading conditions hurt its revenues. Fourth-quarter revenues for the investment banking arm were 2.7 billion euros, down 16 percent year-on-year.