Thirty-five-year-old Chennai resident Jaisankar Marimuthu pleaded guilty to one count of conspiracy to commit wire fraud, securities fraud, computer fraud and aggravated identity theft. He had hoped to use unauthorized access to online brokerages to manipulate stock prices, according to prosecutors. At least 95 customers across nine brokerage firms were affected.

The hacking ring involved participants in Thailand alongside India, and operated from February to December 2006. Marimuthu used hacked accounts to make large, unauthorized purchases of securities on behalf of unwitting customers. The bogus trades would be used in a classic 'pump-and-dump' scheme, inflating the prices of stocks that Marimuthu had already purchased. When prices were sufficiently boosted, he and his colleagues would sell off their own investments.

Marimuthu is the second person in the operation to be charged. He was extradited after being arrested in Hong Kong. The accused hacker faces up to seven years in prison and a maximum fine of $500 000.

Traditionally, pump-and-dump campaigns have been carried out using spam mail, in which easily manipulable pink sheet stocks are touted to naïve small investors. The investors, tempted by false inside information, invest in the stocks, allowing the perpetrators to turn a profit.

Renowned spammer Alan Ralsky was recently jailed for four years after masterminding a pump-and-dump stock spamming campaign.