Spammers radically changed their methods from what they used last year. If, at the end of June 2007, 60% of spammers used images in order to make people swallow the bait, the percentage dropped to 3% at the end of June 2008. On the other hand, after conducting a global study, BitDefender researchers noticed the revival of text spam - 70% of the spamming attacks are now text-based, compared with the 20% that was recorded last year.

"Plain-text continues to be the most prolific medium for e-mail spam distribution, especially due to its simplicity, reduced size and extreme versatility," said Vlad Valceanu, head of BitDefender AntiSpam Research Lab.

The methods used to spread malware in the first six months of 2008 were reported as being, in order, downloaders, malicious advertising, bundle applications, social engineering and information websites, autorun and file infectors, email spam and peer-2-peer networks.

As expected, considering the immense number of emails with a medical subject that are received by almost anyone, the team that works in the anti-virus field said that content related to drugs is the most used, worldwide, to spread malicious software. Replica watches placed second in the top of most popular subjects to be delivered by spammers via email.

Phishing tools were also popular in the first half of 2008. Those who were especially targeted were native English speakers from the US, UK or Canada, who were tempted with counterfeited offers, mainly from US banks and other financial institutions. Most of the messages were alarming, in order to make people react impulsively - they were relating about blocking or expiration of accounts, while also asking for private information that was to be used to enhance security.

"Spammers and phishers continued to improve their skills in replicating and forging legitimate message characteristics. However, the simple text e-mails proved their efficiency as well, rounding up the total figure of ID theft victims to 50,000 each month," added Vlad Valceanu.