Data breach notification letters sent to impacted individuals last month revealed that Brenntag had known of the intrusion on April 28, two days after DarkSide began its attack, after which it immediately disconnected affected systems for threat containment.
Brenntag said that DarkSide attackers were able to steal individuals' birthdates, Social Security Numbers, driver's license numbers and some health data, but outside cyberforensic experts sought by the company found no fraudulent use of the stolen data.
Meanwhile, more than 6,700 of the affected individuals have been asked to examine their account statements and monitor free credit reports for identity theft and fraud attempts.
BleepingComputer also confirmed the $4.4 million ransom paid by Brenntag to secure a file decryptor and curb a data leak.