Cryptocurrency exchange Poloniex has had its hot wallets drained by hackers with an estimated loss of around $114 million, several sets of on-chain data show.

A suspected hack was flagged at around 10:55 UTC by blockchain security firms PeckShield and Cyvers. Poloniex announced 12 minutes later that the exchange's wallet had been disabled for maintenance. The hack was later confirmed by Poloniex investor Justin Sun in a tweet.

Various wallets across multiple blockchains appear to have been targeted. Arkham data shows that an Ethereum wallet, now tagged as "Poloniex hacker," sent a total of $114 million worth of tokens from Poloniex in 357 transactions. A wallet on the Tron blockchain also sent around $42 million to various wallets.

Crypto exchanges are common targets for hackers. Two months ago HTX was hacked with a total of $8 million worth of ether (ETH) being drained; South Korean exchange Gdac lost $13 million in April and Deribit lost $28 million in a hot-wallet hack last November.

On-chain data also show the Poloniex hacker bought $20 million worth of tron (TRX), pushing the token's price up by more than 25%.

"We are currently investigating the Poloniex hack incident," Sun tweeted. "Poloniex maintains a healthy financial position and will fully reimburse the affected funds. Additionally, we are exploring opportunities for collaboration with other exchanges to facilitate the recovery of these funds."

Sun added that the exchange is offering a 5% white hat bounty to the hacker with a deadline of seven days before engaging with law enforcement.

UPDATE (Nov. 10, 2023, 12:20 UTC): Updates amount stolen in headline, first paragraph, according to Arkham; adds Justin Sun white hat bounty offer in last paragaph.