The FBI is trying to determine if JetBrains was compromised as part of the SolarWinds attack.

The SolarWinds attack was one of the largest, most damaging hacks against US government and corporate entities. Some experts have said it will take months, or even years, to understand the extent of the damage.

What made the SolarWinds attack so successful was that it was a supply chain attack. Rather than trying a brute force attack, or tricking organizations into installing suspect software, hackers compromised SolarWinds’ Orion IT monitoring and management software. Since this legitimate software is in use by countless organizations, by compromising it and installing a trojan directly in it, hackers were able to hack organizations using Orion IT.

The FBI is now concerned a second application may have been compromised in a similar nature, according to Reuters. JetBrains makes a project management application called TeamCity. Like Orion IT, TeamCity is used by companies around the world, making it extremely important to determine if it was compromised as well.

“We are not aware of any investigation nor have we been contacted by any agencies,” a JetBrains spokesman said. “We are not aware of any vulnerabilities in the product or breaches that would allow for this, nor that any of our customers were affected.”