In February 2021, software giant Ivanti discovered that Chinese hackers had breached the network of Pulse Secure, one of its subsidiaries that provided VPN appliances to dozens of companies and government agencies around the world, according to new reporting by Bloomberg.

The hackers exploited a secret backdoor they had planted in Pulse Secure’s VPN software, Bloomberg reported, citing Ivanti’s chief security officer at the time and other sources. The backdoor allowed the hackers to gain access to 119 other unnamed organizations that used the company’s same VPN product.

Mandiant was reportedly aware of the breaches as well, alerting Ivanti that hackers had exploited the bug to breach European and U.S. military contractors. 

The previously unreported breach is the latest example of how acquisitions, layoffs, and cost-cutting driven by private equity firms helped to compromise the quality and security of Ivanti’s most critical technologies. After private investment giant Clearlake Capital Group acquired Ivanti in 2017, Bloomberg reported rounds of cuts — particularly in 2022 — affecting employees who had deep institutional knowledge of the company’s products and their security.

Ivanti and Mandiant did not respond to a request for comment. 

Bloomberg’s findings echo earlier reporting into rival provider of remote access tools, Citrix, which had large scale layoffs following a 2022 deal by Elliott Investment Management and Vista Equity Partners to buy the company. Like Ivanti, Citrix has been mired by cybersecurity incidents and critical flaws in recent years. 

Ivanti’s VPN products have been the cause of at least two other major attacks since. 

In early 2024, U.S. cybersecurity agency CISA ordered all federal agencies to disconnect their Ivanti VPN appliances within two days because hackers were actively exploiting vulnerabilities that were unknown to Ivanti at the time. Ivanti also warned customers last year that hackers were exploiting another critical flaw in its Connect Secure product to hack corporate customers.