
According to Sophos, police report that the suspected email lottery scams were sent via piggybacking on a neighbour's Wi-Fi internet connection without permission.
"If you haven't properly secured your Wi-Fi connection you are effectively leaving the front door open for anybody close by to take advantage of it," said Graham Cluley, senior technology consultant at Sophos.
"Everyone running a wireless access point needs to learn how to stop unsavory characters from using it to spew out their spam messages, download illegal content, or steal information."
As a Wi-Fi security procedure Sophos suggested users should implement: encryption; strong passwords, not the default password; MAC address filtering and restrict internet access to certain hours.
Furthermore, users should not broadcast the name of their wireless network and should make sure PCs are properly secured with up-to-date anti-virus, security patches and client firewall software.
"If an email sounds too good to be true, it probably is. Emails scams like this arrive in the inboxes of many every day of the week, all around the world - and clearly some people are falling for them," said Cluley.