Yahoo Japan Data Breach: 22M Accounts Exposed

Yahoo breach could have compromised 10% of all Yahoo user credentials. Meanwhile, Syrian Electronic Army targets <i>The Financial Times</i>.

Mathew J. Schwartz, Contributor

May 20, 2013

5 Min Read

The Syrian Electronic Army: 9 Things We Know

The Syrian Electronic Army: 9 Things We Know

(click image for larger view)
The Syrian Electronic Army: 9 Things We Know

Yahoo disclosed Friday that a breach at Yahoo Japan may have exposed 22 million login names to attackers.

"We don't know if the file [containing 22 million user IDs] was leaked or not, but we can't deny the possibility, given the volume of traffic between our server and external terminals," read a statement issued Friday by Yahoo Japan. Yahoo is the country's most-visited website, and is jointly owned by Yahoo and Japanese network operator Softbank.

Yahoo Japan posted a link to a related breach notification on its homepage, and said it was contacting affected users and had strengthened network security in the wake of the attack. Yahoo Japan also recommended all users -- as of last year, the company had about 24 million users -- change their passwords, and added a tool on its homepage that allowed users to check if their ID was at risk from the suspected breach.

[ Defense Department and Google are partnering to tighten cloud user authentication. Read more at Google, DISA Launch User ID Pilot. ]

Yahoo Japan's users, however, can't change their login IDs -- which sometimes appear publicly; for example, when users post comments on shopping sites -- without losing access to their current account's email and stored data, reported PC Advisor. But after Yahoo Japan discovered malware on its servers last month that had extracted -- but not exfiltrated -- information relating to 1.27 million of its users, the company added a "Secret ID" capability, which allows users to use a separate ID only for logging on.

Yahoo officials said they discovered the unauthorized access Thursday. The potential data breach affects 10% of Yahoo's user base.

Yahoo was last in the data breach headlines in July 2012, when the company confirmed that an "older file" containing 450,000 usernames and passwords associated with its Yahoo Voices service had been leaked online. At the time, it said that only 5% of the leaked passwords were still valid. "D33Ds Company" took credit for the hack, saying it had been accomplished via SQL injection attack. The group said it had leaked the information "as a wake-up call, and not as a threat" to Yahoo to fix the vulnerability, the specifics of which the hackers didn't publicly detail.

In other hacking news, the Financial Times (FT) Friday became the latest victim of Syrian hackers, after its website and multiple Twitter accounts were compromised via spear-phishing attacks. "Syrian Electronic Army Was Here," read 12 posts to various FTTwitter feeds. Multiple fake messages were also posted to the newspaper's Twitter account.

The Syrian Electronic Army claimed to have compromised 17 of the newspaper's Twitter accounts as well as its website, and posted what it said was the username and password ("Gar1eth") for a marketing executive at the paper.

"We have now locked those accounts and are grateful for Twitter's help on this," said Robert Shrimsley, the managing editor of, reported the FT.

The newspaper is the latest media organization to have seen its Twitter feeds hacked by the Syrian Electronic Army, which supports Syrian President Bashar al-Assad. The group has preciously compromised an Associated Press feed, which it used to issue a fake alert that explosions had occurred in the White House. Other targets have included the BBC, the Guardian, National Public Radio and satire site The Onion.

Earlier this month, Twitter warned news and media outlets to expect further attacks.

To halt Twitter account takeovers, security experts have recommended using a dedicated PC for tweeting, or employing an intermediary social media management such as Hootsuite to block the spear-phishing attacks the group often uses to obtain credentials. They've also called on Twitter to implement two-factor authentication. But a "secret ID" service of the Yahoo Japan variety would also help Twitter users, since all Twitter usernames are already public, meaning would-be attackers only need to obtain a password to hack into an account.

As with previous Syrian Electronic Army takeovers, some of its FT tweets advanced the group's stated aim "[defending] the Syrian nation against the vicious lying media campaign," referring to perceived inaccuracies in reporting on the Syrian civil war. One bogus FT tweet, for example, read: "Jabhet A-Nosra terrorists executed innocent citizens," referring to the militant jihadist group that currently controls large parts of the rebel-held areas of northern Syria. Some leaders of that group recently pledged allegiance to al-Queda.

Interestingly, the FT last month interviewed a self-described member of the Syrian Electronic Army who calls himself "Th3Pr0." "All the countries who support the terrorists groups in Syria are targets for us -- their media/government website/social media accounts," Th3Pr0 said. "Our demands [are] to stop suspending our accounts and domain names so we can enjoy the 'Freedom speech of America.'"

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About the Author(s)

Mathew J. Schwartz


Mathew Schwartz served as the InformationWeek information security reporter from 2010 until mid-2014.

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