Norway-based browser company Opera advised Sync customers on Friday to change their passwords after someone hacked the service and possibly accessed user data.
Sync allows Opera browser users to easily synchronize their bookmarks and favorite sites when switching between multiple devices. Roughly 1.7 million of Opera’s 350 million users created a Sync account.
The attack that hit the Sync service was detected by Opera last week. The company claimed the intruders were quickly blocked, but some data, including Sync usernames and passwords, may have been compromised. The investigation is still ongoing.
“Although we only store encrypted (for synchronized passwords) or hashed and salted (for authentication) passwords in this system, we have reset all the Opera sync account passwords as a precaution,” Opera’s Tarquin Wilton-Jones explained in a blog post.
Users have been advised to change not only their Sync passwords, but also any other third-party website password synchronized with the service. Some users have complained that they have hundreds of synced passwords, although Opera has pointed out that synced passwords are not the same as the ones stored in the browser’s built-in password manager.
Opera users who haven’t created an account for the Sync service don’t need to take any action as they are not affected by the breach.
This was not the first time Opera suffered a data breach. In mid-2013, the company informed customers that malicious actors had accessed its internal network and managed to steal a code-signing certificate that they used to sign malware.
Opera announced this summer that it has entered an agreement with a Chinese consortium that includes the security firm Qihoo 360 to sell some of its business units for $600 million. This includes the mobile and desktop browsers, performance and privacy apps, Opera’s technology licensing business (except Opera TV), and the company’s 29 percent share in the Chinese joint venture nHorizon.
The Chinese consortium initially also wanted to buy Opera’s advertising and marketing business, TV operations and game-related applications for a total of $1.2 billion, but the deal was scaled down to prevent a delay caused by U.S. privacy concerns.
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