Criminals are hacking into people's computers by sending a fake email which offers credit for iTunes music, games and video. Users are told they have been sent 50 dollar worth of iTunes store credit and need to open an attached ZIP file to find out their certificate code. According to the Eleven security blog, this attached file contains a Malware program known as Mal/ BredoZp-B which can allow hackers to gain access to the recipient's computer.

The software opens up a backdoor on the users' computers and may also capture passwords and other information, said PCthreat.com. It says the code may also slow down the infected computer's performance and make files disappear. The malware can be removed with the use of anti-spyware tools. The attack appears to have been timed to coincide with Black Friday, one of the US's busiest shopping days. Black Friday was the name used by Philadelphia's police department in the 1960s to describe the day after Thanksgiving because of all the traffic jams caused by people visiting the city's stores.

Many retailers now view it as the start of the Christmas shopping season and mark the day with one-off discounts and other special offers. This period has also become one of the most popular times for Internet scammers.