HOUSTON (Reuters) - Top US oilfield services firm Halliburton ( HAL ) on Wednesday was hit by a cyberattack, according to a person familiar with the matter.

The attack appeared to impact business operations at the company's north Houston campus, as well as some global connectivity networks, the person said, who declined to be identified because they were not authorized to speak on the record.

Spokespeople for the company did not immediately respond to requests for comment. The company has asked some staff not to connect to internal networks, the person said.

Cyberattacks have been a major headache for the energy industry. In 2021, hackers attacked the Colonial Pipeline with ransomware, causing a days-long shutdown to the major fuel supply line.

That breach, which the FBI attributed to a gang called DarkSide, led to a spike in gasoline prices, panic buying and localized fuel shortages. It also created a major political headache for President Joe Biden as the U.S. economy was starting to emerge from the COVID-19 pandemic.

Several major U.S. companies have suffered ransomware attacks in recent years, including UnitedHealth Group ( UNH ), gambling giants MGM Resorts International ( MGM ), Caesars Entertainment CZR.O and consumer good maker Clorox.

(Reporting by Liz Hampton in Denver and Chris Sanders in Washington)