Kraft Heinz shares cratered nearly 25 percent in Friday's premarket, a day after the company wrote down $15.4 billion on two of its most iconic brands, slashed its dividend and disclosed it received a subpoena from the Securities and Exchange Commission on its accounting policies and internal controls in October.

Before the market's open Friday, Kraft shares were trading at about $36.30, far below its 52-week low of $41.60, set in late December. The stock, which has a market value of about $58.8 billion, has fallen nearly 29 percent over the past year, but had been up nearly 12 percent since January.

Higher costs coupled with the $15.4 billion impairment charge on the company's namesake Kraft and iconic Oscar Mayer brands led to Kraft Heinz reporting a net loss of $12.61 billion in the fourth quarter. It earned $8 billion in the year-earlier period. Revenue and earnings results fell well short of Wall Street's estimates.

The company cut its dividend to 40 cents per share, a 36 percent decrease from its previous quarterly dividend of 62.5 cents per share. Kraft said it took the measure because it's seeking to deleverage faster and "provide greater balance sheet flexibility."

In the wake of the news, Kraft received several downgrades. Deutsche Bank cut Kraft to hold from buy even though it said management is taking the right strategic steps.

"However, our visibility with respect to the depth, duration, and general proﬁtability eﬀects of such customer- and consumer-building into 2019 is less clear and lowers our conviction on the name," analyst Rob Dickerson said in a research note.

PiperJaffray cut Kraft Heinz to neutral from overweight, citing its concerns over the write down of its marquee brands.

"We believe these impairments validate fears that KHC may have been more focused on costs than building brand equity, and even if management now has 'seen the light', we are now concerned that its brands lack the equity to drive pricing power needed to compete and drive growth in a sustainable way," said analyst Michael Lavery.

Since merging Kraft and Heinz in 2015, the combined company has slashed $1.7 billion in costs. The moves helped Kraft cut costs, though some had wondered if this came at the expense of Kraft making the investments needed to survive in today's tough environment. Packaged food is falling out of favor with consumers, who are looking to eat fresh foods or are buying niche, upstart brands or less expensive private label products.

Kraft also disclosed the SEC subpoena is part of an investigation into its procurement and accounting policies. The company said it launched an internal investigation into the matter after receiving the subpoena. Following its investigation, Kraft Heinz said it posted a $25 million increase to the cost of products sold after determining it was "immaterial to the fourth quarter of 2018 and its previously reported 2018 and 2017 interim and year to date periods."

The company said it is cooperating fully with the SEC. Kraft Heinz also said it is improving internal controls and procedures to prevent something like this from recurring. The company said, however, that it does not expect this issue to be material to financial statements for this period or previous ones.

"We continue to cooperate fully with the SEC, and at this time the Company does not expect matters subject to the investigation to be material," a spokesman said Friday in an email to CNBC.

—CNBC's Christina Cheddar Berk contributed to this report.