According to the MessageLabs Intelligence E-mail Security report, which looks at e-mail developments in the first six months of 2004, the dominant trend is one of converging attack methods, with financial gain the prime motivation.
The report reveals that 63.5% of all e-mail intercepted by the firm between January and June was spam, up from 37.9% for the same period last year, and 1.5% for the same period in 2002.
Just over 8% of e-mails contained a virus, up from 0.5% in 2003, and 0.3% in 2002. Of those viruses intercepted between January and June, the majority, including the MyDoon, Netsky and Bagle viruses, had the potential for spam distribution.
According to Paul Wood, Chief Information Security Analyst at MessageLabs:
"The boundaries between viruses and spam have been eroded, and commercial gain would seem to be the driving force. There is little or no profit to be gained from simply distributing viruses, but when you consider the income that can be earned from spam you have an altogether more attractive proposition."
Phishing - where e-mails appearing to come from legitimate businesses are sent in an effort to fish for recipients' financial details - has also grown dramatically, with over 1.5 million phishing e-mails intercepted by MessageLabs in the relevant period. Again these scams involve a convergence of viruses, spam and fraudulent web sites for financial gain.
Spyware – a type of software that secretly forwards information about a computer user's on-line activities to another individual or company – seems to be another tactic for the spammers.
"The convergence of spyware and spam is just the latest milestone in the evolution of spamming techniques, as spammers, virus writers and hackers are combining their techniques in an attempt to increase the efficiency of e-mail security attacks," said Woods.
There is also a suggestion that spammers send seasonally-adjusted spam. According to security firm Clearswift, levels of pornographic spam have shot up over the summer months for the second year in a row – an increase of almost 350% since June. And in what the firm suspects is an attempt to match supply with demand, healthcare spam (mostly Viagra) has also risen significantly.