Cybercriminals made off with $100 million in cryptocurrency after hacking Horizon, a so-called blockchain bridge, the company says.

Harmony, the blockchain startup behind Horizon, tweeted late Thursday that that it had discovered the theft and was working with forensic specialists and law enforcement in hopes of tracking down those responsible. 

Blockchain bridges allow users to transfer cryptocurrencies between blockchains. Harmony said that its separate bridge used for bitcoin wasn't affected by the hack and that its funds and assets are safe. 

"The team is all hands on deck as investigations continue," Harmony tweeted. "We will keep everyone up-to-date as we investigate this further and obtain more information."

The hack and ransacking of Horizon wasn't the first this year. In March, cybercriminals stole about $620 million worth of cryptocurrency from a network used to process in-game transactions for Axie Infinity, one of the world's most popular NFT video games.

Meanwhile, the values of bitcoin and other cryptocurrencies have plunged this year as coin holders sold their holdings due to the downturn of the economy. The decline in value has affected crypto exchanges, with Coinbase and Crypto.com cutting their workforces.