The once was the pioneer of the internet, Yahoo! is experiencing yet another hacking incident. The company has discovered that its database of users have been breached by hackers using "forged cookies."
This method exploits the strings of data which are used across the web that can sometimes allow people to access online accounts without re-entering their passwords.
The hack has breached Yahoo!'s user database that include personal details as well as credit cards.
While Yahoo! has invalidated those sophisticated cookie forging exploit, the company acknowledges that potential malicious activities as a result of the breach, could pose damage to the already-affected users.
Users that had their accounts compromised are receiving an email from Bob Lord, Yahoo!'s chief information security officer, that warns about the data security issue. The company said that almost every affected user had been notified as of February 15th, 2017. But Yahoo! isn't staying still as investigations are still ongoing.
"The investigation has identified user accounts for which we believe forged cookies were taken or used," said a company spokesperson. "Yahoo! is in the process of notifying all potentially affected account holders."
This is the third hack Yahoo! experienced since 2013. Yahoo! is warning users of potentially malicious activity on their accounts between 2015 and 2016.
Yahoo! didn't say how many accounts were compromised in this incident. It's advised that all Yahoo! account owners should check whether they receive an email from Bob Lord which includes security recommendations for protecting their accounts.
And for those that are affected, they should review any suspicious activities regarding their account, and should avoid responding to any unsolicited messages.
The announcement by Yahoo! follows a series of high-profile breaches the company reported. Last September the Sunnyvale giant revealed it had suffered a massive attack affecting more than half a million users. This was followed by another breach, putting more than a billion users at risk.
The news is a huge blow for Yahoo!. The company realized the breach shortly after reports said that Verizon is finally closing in on its prolonged negotiations to acquire it. While the two companies initially agreed on a $4.83 billion offer, Verizon may offer a big price cut following the many security breaches Yahoo! experienced.
Yahoo! is also under investigation by the Securities and Exchange Commission for delaying its data breach announcements for years.
Further reading: Verizon Acquires Yahoo!: The Beginning Of A New Beginning