Sony is sending out notices to some current and former Sony Interactive Entertainment (SIE) employees warning that their personal information was compromised in a system breach that occurred in May. The letters went out to about 6,800 affected individuals, as reported by Bleeping Computer. The publication also received confirmation from Sony that another breach occurred in September.

A ransomware group known as Cl0p claimed responsibility for breaking into a Sony server in June. The breach occurred via a vulnerability in the file-sending MOVEit Transfer platform that SIE was using. Sony is one of many organizations that have been affected by MOVEit cyberattacks.

Progress Software, the creator of MOVEit Transfer, told its clients (including Sony) about a vulnerability in its platform on May 31st, Sony says in the letter. After the warning, SIE discovered that a breach occurred on May 28th and that hackers downloaded data off the server.

The server included personally identifiable information of US-based employees, and Sony is providing credit monitoring services to those affected. Sony says it has since fixed the vulnerability.

Sony launched an investigation last month into a second breach in which hackers acquired 3.14GB of data. Sony confirms this server is located in Japan and is used for internal testing for its Entertainment, Technology and Services business, according to a statement sent to Bleeping Computer. Sony is investigating this incident and has taken the server down. Hackers that were responsible leaked files that included data from the SonarQube platform, certificates, a license generator, Creators’ Cloud, and more. Sony said that this latest incident had “no adverse impact on Sony’s operations.”