Hackers have obtained the personal information of an unknown number of PlaySpan Marketplace users, the company has reported.
The compromised data includes user IDs, email addresses, and encrypted passwords.
There was no evidence any credit, debit, or prepaid card data was accessed or exported from the PlaySpan network, said the company.
All user accounts have been locked, and the Marketplace has been taken offline while an investigation is completed.
PlaySpan’s virtual goods monetisation platform is used in more than 1,000 games to power transactions, but the company's Marketplace is a completely separate service.
“When PlaySpan detected the breach, we immediately shut down the hacker's access to our systems and took steps to protect our customers' PlaySpan accounts,” said PlaySpan.
“We then commenced a comprehensive forensic analysis and are working with law enforcement to investigate the crime.”
All Ultimate Pay account passwords have automatically been changed. Other customers are advised to change their passwords manually.
“We sincerely apologize for any frustration or inconvenience this incident has caused our customers,” said PlaySpan.
“We know PlaySpan's business depends on consumer trust. Security is a top priority for us, and we are redoubling our efforts to strengthen PlaySpan's overall system security.”
More than two million customers have registered accounts on the PlaySpan marketplace, of which a spokesperson said there are 117,000 active users.
It has been erroneously reported that Guild Wars, RuneScape, and Eve Online credentials are stored by PlaySpan.
Unfortunately a list of games that use the service's Marketplace functionality has not been made available by the company.
However, it is known that World of Tanks uses the PlaySpan service. Developer Wargaming.net wrote the following on its official WoT forums:
"If your Playspan Marketplace account email is different from your World of Tanks email, then you do not need to change your game account information, as our internal game data was not compromised.
"If you are a registered PlaySpan Marketplace user, Playspan Marketplace recommends you change your marketplace account password.
"If you are a registered PlaySpan Marketplace user, and you used the same email and password for your World of Tanks account, we suggest you change your World of Tanks password."