Oil and gas giant Halliburton has confirmed in a filing today to the Securities and Exchange Commission (SEC) that data was stolen in the recent attack linked to the RansomHub ransomware gang.

The form 8-K filing mentions that an unauthorized third party accessed and exfiltrated sensitive information from Halliburton systems, and the company is now in the process of determining the exact scope of the breach.

“The Company believes the unauthorized third party accessed and exfiltrated information from the Company’s systems,” reads Halliburton’s latest 8-K Form filing to the SEC.

“The Company is evaluating the nature and scope of the information, and what notifications are required.”

Halliburton originally disclosed the security breach via an 8-K form filing on August 22, mentioning that it detected unauthorized access to its systems without sharing many details about the nature and scope of the incident.

Later in the month, BleepingComputer learned that behind the attack was the RansomHub ransomware gang and that the oil giant was struggling with an extensive IT system and business disruptions.

An email Halliburton sent to suppliers revealed that the company had to take certain systems offline to contain the attack and had contracted Mandiant to help them with the investigation and remediation efforts.

The latest 8-K Form confirms the operational disruptions internal staff previously reported on Reddit discussions.

“The incident has caused disruptions and limitation of access to portions of the Company’s business applications supporting aspects of the Company’s operations and corporate functions,” Halliburton explains.

Financial and customer impact

Halliburton has not shared details of the attack with the media or its customers, causing confusion and concern to other firms who had their systems connected to Halliburton’s platform and feared infections.

The company now says it is communicating with customers and other stakeholders about the incident and assessing the need for notifications. At the same time, it acknowledges the risks of litigation and changes in customer behavior.

Regarding the financial impact, Halliburton says the incident is unlikely to have material impact. Heavier financial burdens from potential legal actions or reputation risks are not ruled out.