What is the 'free stock trading book' scam that the govt has warned about?

The government has issued a warning about a new scam, wherein cybercriminals are distributing free books on stock trading. These books are distributed through ads on Facebook and Instagram and investment classes are also organised through WhatsApp groups, it said. "If you get a free book on 'Stock Trading' delivered at your home...it may be a trap," the government added.