Software giant Microsoft revealed today a security breach that happened last month in December 2019.
The OS maker, in a blog post, said that an internal customer support database that was storing anonymized user analytics was unintentionally uncovered online without appropriate defenses between December 5 and December 31.
The database was identified and conveyed to Microsoft by Bob Diachenko, a security researcher.
The drippy customer support database comprised a bunch of five Elasticsearch servers, a technology used to streamline search operations. All five servers kept the same data, seeming to be mirrors of each other.
Diachenko said Microsoft held the uncovered database on the same day he reported the issue to the OS maker, notwithstanding being New Year’s Eve.
“I have been in touch with the Microsoft team helping and supporting them to properly investigate it.”
The servers contained almost 250 million entries, with information such as email addresses, IP addresses, and support case details. The company said that most of the records didn’t comprise any personal user information.
“As part of Microsoft’s standard operating procedures, data stored in the support case analytics database is redacted using automated tools to remove personal information,” Microsoft said.
For these cases, Microsoft said it started informing affected customers today, though it also added that it “found no malicious use” of the data.
Microsoft held the accidental server exposure responsible for misconfigured Azure security rules it installed on December 5, which it now rectified.