Massive Cybersecurity Breach at Yahoo Reading Time: 3 minutes

On Sep 22, 2016, Yahoo issued a press release: “A recent investigation by Yahoo! Inc. has confirmed that a copy of certain user account information was stolen from the company’s network in late 2014 by what it believes is a state-sponsored actor. The account information may have included names, email addresses, telephone numbers, dates of birth, hashed passwords (the vast majority with bcrypt) and, in some cases, encrypted or unencrypted security questions and answers.”

Massive Cybersecurity Breach at Yahoo

Yahoo states that it has not yet completed the investigation, and adds that “The ongoing investigation suggests that stolen information did not include unprotected passwords, payment card data, or bank account information; payment card data and bank account information are not stored in the system that the investigation has found to be affected. Based on the ongoing investigation, Yahoo believes that information associated with at least 500 million user accounts was stolen and the investigation has found no evidence that the state-sponsored actor is currently in Yahoo’s network. Yahoo is working closely with law enforcement on this matter.”

At least 500 million user accounts – Wow! Could the breach be blamed on lack of sufficient cybersecurity or that Yahoo could not face the brunt of the purported “state-sponsored” attack.

Cybersecurity experts warn that the breach is a massive disaster that can have severe ramifications. Cybercriminals who have access to the data could now resort to “credential stuffing” cyber attacks. Now, what is “credential stuffing”? The stolen username and passwords are used for trying to gain access to other websites. This attack process is quite easy now with available software. Though credential stuffing has a quite low rate of success, considering 500 million user accounts means thousands of other accounts could be hacked into. “This was why we were warned not to use the same username and password for multiple websites. But how many do follow the security measure.”

Yahoo claims that most of the passwords were encrypted and could not be broken. This attack took place in 2014, and was discovered only in July 2016 when cyber criminals started to offer stolen Yahoo account credentials for sale. Yahoo uses multiple encryption protocols for passwords, and it is possible that one of them had been broken.

Yahoo also alerts that some security questions were also compromised. Hence, users who use the same credentials for accessing multiple accounts must change them immediately.

Precautions Against Cybersecurity Breaches

Most precautions are actually necessary standard procedures.

  • Change your Yahoo account credentials immediately
  • Change the security questions and answers to your Yahoo account
  • If you have used the same login credentials (user name, passwords) or security questions for other websites, then change them immediately
  • Do not use the same login credentials for multiple accounts
  • Change your security passwords on a regular basis.
  • Be wary of phishing emails that appear to be genuine. They may contain the stolen credentials and would look pretty convincing.
  • Be wary of phishing phone calls that appear authentic with stolen Yahoo data.
  • Use strong passwords that are a mix of lower case and upper case alphabets, numerals and special characters
  • Make use of two-factor authentication or other extra-precautionary measures where available.

Related Resources:

How To Improve Your Company’s Cyber Security Readiness

Why you’re putting your network at risk with a defensive approach to malware

The Seven Advantages of Hiring a Cyber Security Provider

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