Corporate travel firm CWT was stung for $4.5 million after being targeted by ransonware hackers.
According to Reuters, hackers paralyzed a large amount of data and demanded bitcoin payment to restore it.
They claimed to have knocked 30,000 computers offline.
CWT confirmed the cyberattack but understandably is saying very little about the incident.
"We can confirm that after temporarily shutting down our systems as a precautionary measure, our systems are back online and the incident has now ceased," CWT said in a statement.
"While the investigation is at an early stage, we have no indication that personally identifiable information/customer and traveler information has been compromised."
CWT said it immediately informed law enforcement.
Hackers infected the CWT system with a ransomware program called Ragnar Locker, which allegedly disabled thousands of computers.
The hackers had earlier demanded $10 million to restore the data.
It is unclear what data hackers had access to or if any of its major corporate customers were impacted.
Minneapolis based CWT posted revenue of $1.5 billion in 2019 and says its customer base includes more than one third of S&P 500 companies.
by Ray Montgomery, US editor
