China’s hackers-for-hire take government officials out for lavish banquets, binge drinking and late-night karaoke with young women in a bid to win favor and business, as revealed in a highly unusual leak last month of internal documents from a private contractor linked to Chinese police.

China’s hacking industry is vast in size and scope but also suffers from shady business practices, disgruntlement over pay and work quality, and poor security protocols, the documents show.

Private hacking contractors are companies that steal data from other countries to sell to the Chinese authorities. Over the past two decades, Chinese state security’s demand for overseas intelligence has soared, giving rise to a vast network of these private hackers-for-hire companies that have infiltrated hundreds of systems outside China.

Though the existence of these hacking contractors is an open secret in China, little was known about how they operate. But the leaked documents from a firm called I-Soon have pulled back the curtain, revealing a seedy, sprawling industry where corners are cut and rules are murky and poorly enforced in the quest to make money.