As Yahoo poises to sell up to Verizon, it may have some bad news to share.

Recode reports:

Yahoo is poised to confirm a massive data breach of its service, according to several sources close to the situation, hacking that has exposed several hundred million user accounts. Sign up to our newsletter

Security news, advice, and tips. While sources were unspecific about the extent of the incursion, since there is the likelihood of government investigations and legal action related to the breach, they noted that it is widespread and serious. Earlier this summer, Yahoo said it was investigating a data breach in which hackers claimed to have access to 200 million user accounts and was selling them online. “It’s as bad as that,” said one source. “Worse, really.”

This summer a hacker calling themselves “Peace” was reportedly trying to sell 200 million Yahoo usernames, passwords and dates of birth on dark market websites.

What we don’t know is whether the alleged stolen login credentials were collected through phishing attacks, a breach at a different site where Yahoo users were using the same passwords), or a serious security breach at Yahoo itself.

Of course, we have to wait to see if Yahoo does make an announcement about a hack or not, and if they do what the nature of the claimed data breach might be. Until then, there’s a lot of speculation.

As before, my advice to Yahoo (and other internet) users is that your online accounts will be a whole lot safer if you have not made the mistake of reusing passwords between different sites, and have enabled two-step verification.

If a massive Yahoo hack is confirmed there will inevitably be many people quick to blame the firm for exposing their information. Not to pass the buck, but everyone going online today needs to be sensible about their security and take the necessary precautions and steps to reduce the chances of their own accounts being compromised.

Even if this current scare ends up not impacting your account, there is always the danger that you could become a victim in the future.

Update: Yahoo confirms: hackers stole 500 million account details in 2014 data breach

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