The Securities and Exchange Commission on Thursday announced it was fining a manufacturer $1 million for not disclosing certain executive perks—the latest evidence of the agency’s stepped-up aggressiveness against companies that fail to disclose benefits unrelated to work, such as use of a company plane.

According to the SEC, Lake Oswego, Oregon-based The Greenbrier Cos. did not disclose a range of benefits, including compensation its former chairman and CEO, William Furman, received after he and other executives used his personal plane for business.