Vietnam, along with the US, India and Germany, have the greatest number of Internet users affected by phishing attacks, with the total number doubling since last year, computer security company Kaspersky Lab says.

A study conducted by the company found that the number of Internet users worldwide who faced phishing attacks over the last 12 months increased from 19.9 million to 37.3 million, a rise of 87 percent.

Facebook, Yahoo, Google and Amazon are among main targets of cyber criminals, it said.

The study, which was based on data from the Kaspersky Security Network cloud service, found that what was once a subset of spam has evolved into a rapidly growing cyber threat in its own right.

Phishing is a form of internet fraud in which criminals create a fake copy of a popular site (an email service, an Internet banking website, a social networking site ect.) and try to lure the users to these rogue web pages.

The unsuspecting user enters their login information and passwords into these carefully forged websites as they normally would, but these access credentials are instead sent to the cyber criminals.

The scammers can then use this stolen personal information, bank credentials, or passwords to steal the users’ money, to distribute spam and malware via the compromised email or social networking accounts, or they can simply sell their databases of stolen passwords to other criminals.

For a long time, phishing was regarded as a variation of typical spam email.

However, the date from this survey shows that email is no longer the most common delivery mechanism for phishing communications. Nearly 88 percent of attacks came from links to phishing pages which people followed while using a web browser, Skype, or otherwise interacting with the computer.

Kaspersky Lab specialists also compared data on phishing attacks from over 50 million Kaspersky Security Network users between May 1, 2012 and April 30, 2013 with figures for the corresponding period in 2011-12.

“The volume and variety of phishing attacks detected during the survey indicates that phishing is not merely one tool among many for the illegal enrichment of fraudsters, but represents a significant and visible threat.

“These attacks are relatively simple to organise and are demonstrably effective, attracting an increasing number of cyber criminals to this type of illegal activity,” said Nikita Shvetsov, Deputy CTO (Research) at Kaspersky Lab.

Therefore, consumers must understand phishing tactics so as to protect themselves against attacks, Kaspersky Lab specialists say.-