Yahoo! Japan breach possibly leaks 22 million user IDs

Attackers recently broke into systems at Yahoo! Japan and may have accessed some 22 million user IDs (representing 10% of all Yahoo! users). While the internet giant didn’t disclose how attackers got in – and stressed that no other personal information could have been accessed – this still represents a threat to users, who may receive spam messages containing malware or links to malicious websites.

Here’s what a few security experts had to say:

“Many people use the same passwords for work as they do for personal websites,” Eric Chiu, president & founder of HyTrust (, the cloud control company pointed out. “If an attacker is able to gather these account passwords through phishing emails, it can lead to compromises of corporate networks in order to siphon data.”

So be alert. Attackers will try to get you to provide passwords and there are many ways they can do this. For example, a phishing email can trick you into providing it by making you think you’re entering for a valid purpose by a trusted organization. Also, once you or your PC has been compromised, attackers can gain access to your company’s network and do much worse damage.

Chiu also warns organizations about security monitoring tools, saying, “Unfortunately, most security monitoring solutions today are incapable of detecting good insider activity from bad. And, as organizations move critical infrastructure and applications to the cloud, the risk of attackers posing as insiders to gain access is compounded, since cloud and/or virtualized data can be copied, deleted, and/or moved from anywhere on the globe virtually undetected.”

Security organizations should look at Role-Based Monitoring (RBM) as a much more effective approach and, Chiu says, the industry’s future direction.

Chiu warns that attackers can also potentially destroy an entire corporate datacenter in a matter of minutes. These risks highlight the need for companies to secure access with technologies and processes that can detect and prevent bad actions in real-time, he said.

Nathaniel Couper-Noles, senior security consultant at Neohapsis (, a security and risk management consulting company specializing in mobile and cloud security services, said: “The information possibly leaked [in the Yahoo! Japan breach] can be useful to attackers indirectly, for example by facilitating further attacks such as social engineering or password guessing.”

So again, be wary when receiving email messages from people you don’t know, and even those you DO know when messages look suspicious. To avoid becoming victim of an attacker, don’t click any links, provide any information, or even respond, and further, don’t even open or read these message in a “preview pane.”

Feel free to add your guidance to ours by commenting, and stay safe online!