Tech giant Tesla was the target of a $1 million ransomware attack, according to the Federal Bureau of Investigation.

According to the FBI, 27-year-old Russian man Egor Igorevich Kriuchkiv was arrested on August 22 for conspiring to execute malware at Tesla’s Gigafactory Nevada. The hacker was part of a ransomware group that has reportedly committed previous ransomware attacks, though the FBI has yet to release information on the other targets.

Tesla CEO Elon Musk confirmed the attempt on Twitter, calling the foiled plot a “serious attack.”

Much appreciated. This was a serious attack.

— Elon Musk (@elonmusk) August 27, 2020

Kriuchkiv used a tourist visa to travel to the U.S. in July, in the hopes of convincing a Tesla employee to help introduce ransomware to Tesla’s servers.

The Russian-speaking employee then contacted informed both Tesla and the FBI about the proposed scheme. The employee, who was not publicly identified, was then used as a part of a month-long sting operation in which Kriuchkiv offered him $1 million in exchange for placing the malware in Tesla’s servers.

The sting operation not only revealed the ransomware plans for Gigafactory Nevada, but gave the FBI insight into previous attacks and the Russian group behind them. In the 25-page FBI complaint against Kriuchkiv, the Russian citizen has been arrested on counts of conspiracy to intentionally cause damage to a protected computer.

Digital Trends reached out to Tesla for comment and will update this story when we hear back.

Ransomware has been a common tactic used by hackers to extort money. Earlier in August, Garmin reportedly paid millions in a ransomware attack that took down server access for over two weeks.