San Francisco (CNN Business) Slack has reset the passwords of thousands of accounts after receiving new information about a hack that took place in March 2015.

Slack WORK In a release on Thursday,said it would reset the passwords of approximately 1% of its accounts. In a securities filing from April 2019, Slack said over 10 million people used its platform daily in the first three months of the year.

Slack, which has been widely adopted in workplaces, is a chat platform that allows people to quickly — and often informally — message one another.

The company said the only affected accounts are those created before March 2015 that have never had a password change. According to the release, 99% of Slack users joined after March 2015 or have changed their password since joining.

account managers to launch team-wide password resets and forced log-outs across all devices. At the time of the 2015 hack, Slack said there was unauthorized access to one of its databases containing profile information and encrypted passwords. It blocked the access, reset passwords and released two-factor authentication as an extra security measure. (Two-factor authentication confirms someone's identify by requiring a verification step in addition to a password.) Slack also released a security feature that allows corporateaccount managers to launch team-wide password resets and forced log-outs across all devices.

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