Opera issued a warning to users Friday that it detected a hack in its sync system that may have given hackers access to login details.
“Earlier this week, we detected signs of an attack where access was gained to the Opera sync system. This attack was quickly blocked. Our investigations are ongoing, but we believe some data, including some of our sync users’ passwords and account information, such as login names, may have been compromised,” said Opera in a blog post.
The service made it clear it only stores encrypted (for synchronized passwords) or hashed and salted (for authentication) passwords in its system. While user passwords are possibly compromised, Opera isn’t taking any chances as it’s reset all sync account passwords.
Opera also sent emails to all Opera sync users to inform them about the incident and ask them to change the password for their Opera sync accounts.
“In an abundance of caution,” Opera also encouraged users to also reset any passwords to third party sites they may have synchronized with the service.
This does not affect the Opera browser users who do not use Opera sync. The total active number of users of Opera sync in the last month is 1.7 million, less than 0.5% of the total Opera user base of 350 million people, said Opera.