Bitcoin online casino Coinroll has warned its customers that their account data may have been compromised.

Late last month, Chris Vickery, a researcher at online security firm MacKeeper, reported discovering an online database containing information from 4,610 Coinroll.com accounts. Softpedia reported that the Coinroll account info was linked to 9.668 Bitcoin wallets.

Vickery reported that the Coinroll database had employed a strong SHA256 cryptographic algorithm to hash the account password strings but the database wasn’t salted with random info, which would have made the passwords nearly impervious to prying eyes. The database also lacked an administrative password, allowing any interested party to download the information.

Last week, Coinroll posted a message to its site alerting customers to the potential breach after receiving reports that some users’ account balances had been stolen. Coinroll insisted that there were only a “few claims” of unauthorized withdrawals but advised all players who’d opened accounts prior to April 7 to change their account passwords.