Avalanche (commonly known as the Avalanche Gang) is a criminal syndicate involved in phishing attacks. In 2010, the Anti-Phishing Working Group (APWG) reported that Avalanche had been responsible for two-thirds of all phishing attacks in the second half of 2009, describing it as "one of the most sophisticated and damaging on the Internet" and "the world's most prolific phishing gang". The name "Avalanche" also refers to the network of websites and systems which the gang uses to carry out its attacks.