The operator of Blik said on social media that the attack was causing intermittent problems with processing payments.
"We are currently observing an external DDoS attack which may temporarily affect BLIK transactions," the company said on X and Facebook, adding that work was underway to restore normal service.
DDoS (Distributed Denial of Service) attacks overwhelm servers with massive amounts of internet traffic from multiple sources, rendering services temporarily unavailable.
In the evening, the company announced that operations had returned to normal.
"Since 6:30 p.m., users should no longer experience problems with transactions," Blik said in an update.
"The system’s infrastructure is now secured, and services are being continuously monitored to ensure smooth operation," it added.
A similar attack disrupted Blik operations on Saturday.
Deputy Prime Minister and Digital Affairs Minister Krzysztof Gawkowski said at the time that Polish payment systems had faced interruptions due to an external DDoS attack targeting the country’s settlement infrastructure.
Blik is Poland’s leading mobile payment system, operated by Polski Standard Płatności, a company jointly owned by major banks.
In 2024, users made 2.4 billion transactions worth over PLN 347 billion (EUR 81.5 billion) via the service.
(ał/gs)
Source: PAP