Randomly checked a few deposit addresses of Kraken exchange users that were poisoned by Huobi addresses, and found that all of them had recent interactions with Kraken's hot wallet (i.e., users who deposited funds into Kraken). Moreover, these addresses had not previously received transfers or deposits from Huobi. In other words, the poisoning was targeted randomly at Kraken's hot wallet. Most likely, this Huobi wallet was hacked and then used maliciously to poison and cause trouble