State-sponsored hackers who unleashed a digital bomb in key parts of Saudi Arabia’s computer networks over the last two weeks damaged systems at the country’s central bank, known as the Saudi Arabian Monetary Agency, according to two people briefed on an ongoing investigation of the breach.

The central bank said in a statement late Friday that its systems hadn’t been breached and that it has continuous surveillance to protect against cyberthreats.

The attacks, which afflicted at least eight government entities, used a computer-killing malware known as Shamoon that is linked to Iran, the two people said. They had the potential to inflict damage on targets across several critical sectors, including finance and transportation.

The investigation is still in its early stages and the determination of responsibility could change, the two people said. The number of entities where damage occurred is likely to grow as the probe continues, a third said.

Iranian officials didn’t respond to repeated requests for comment on the attack.