NEW YORK (TheStreet) -- Shares of Yahoo (YHOO) were gaining in pre-market trading on Thursday even though the company is preparing to announce a data breach of its service later this week, sources told Recode.

The hack impacted several hundred million accounts.

In August, the Sunnyvale, CA-based Internet company said it was aware of a breach in which hackers claimed to have gained access to 200 million accounts to sell online, Recode noted.

A cybercriminal named "Peace" claimed to have put the accounts from 2012 on sale for over $1,800. The stolen data included account names, passwords, birth dates and email addresses.

This widespread and "serious" hack could likely result in government investigation or legal action, sources cited by Recode said.

TST Recommends

The news of the breach comes as Yahoo looks to close the $4.8 billion sale of its core business to Verizon (VZ).

Separately, TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this articles's author.

TheStreet Ratings rated this stock as a "hold" with a ratings score of C.

The company's strengths can be seen in multiple areas, such as its solid stock price performance, revenue growth and largely solid financial position with reasonable debt levels by most measures. However, as a counter to these strengths, we also find weaknesses including deteriorating net income, disappointing return on equity and feeble growth in the company's earnings per share.

You can view the full analysis from the report here: YHOO

Image placeholder title