Detailed Notice on Actions Taken After the 8/31 (Sun) Temporary Maintenance

Hello, this is Blue Archive.

We sincerely apologize for the concern caused by the abnormal display of certain content on August 31 (Sun).

The investigation into the situation has reached its final stage, and we would like to share the details of the incident along with the measures taken, prevention plans, and compensation.

[Detailed Notice on Actions Taken After the 8/31 (Sun) Temporary Maintenance]

■ Issue Overview

- On August 31 (Sun), it was discovered that certain client environment settings had been altered.

- Emergency temporary maintenance was carried out from 8/31 (Sun) 1:22 PM – 7:40 PM (UTC), during which the attack route was examined, and security was reinforced.

■ Cause of the Issue

- The Blue Archive client checks environment settings from the CDN (Content Delivery Network) when launched. These settings are created and managed separately from the game, but records of external access were confirmed.

- Some settings were altered, redirecting to 45.94.31.77 (Netherlands), which caused the issue.

■ Scope of Impact

- Depending on the unauthorized changes, certain content was abnormally displayed (except for specific store/teen builds).

- Symptoms included abnormal banners, the appearance of Koyuki/Miku in Cafe content, and specific YouTube content being displayed. A thorough internal investigation confirmed no other irregularities beyond these.

- These environmental settings only affected the client-side content display.

- We confirm that players’ accounts, game data, and payment information were not affected, as they are operated in a separate database and always revalidated by the game server.

■ Measures Taken

- Restored the CDN environment settings and urgently blocked the distribution path, restricting access to internal use only.

- Limited environment setting permissions to authorized entities and added dual-control measures.

- Reported the incident to KISA (Korea Internet & Security Agency) and are cooperating with the ongoing investigation into the attack and related security measures.

■ Prevention Plans

- Strengthen controls to ensure external access to services is blocked.

- Enhance verification procedures before and after environment setting changes.

- In addition to existing vulnerability assessments, stronger security measures such as penetration testing and bug bounty programs will be conducted across the game client, game servers, and related services.

[Compensation Notice]

We have prepared a compensation package for all Senseis to express our sincere apologies for the inconvenience caused.

■ 8/31 (Sun) Temporary Maintenance Compensation

- Eligible: All Senseis

- Compensation:

Distribution Period: 9/1(Mon) 3:00 PM – 9/8(Mon) 2:59 PM (UTC)

(Mail storage: 7 days, 1 time per account)

* Additional details regarding unreceived rewards for players who purchased the Monthly Pyroxene Pack / Half Monthly Pyroxene Pack / 2-Week AP Pack will be provided in a separate notice.

We will continue to do our utmost to provide a safe and secure environment for all Senseis.

Thank you.