MessageLabs, Inc., a New York-based email security company, says spam now makes up 50 percent of all corporate email. Analysts there also note that they stopped 79.7 million spam emails last month. That's 10 million more than the total number stopped in all of 2002.
Spam has grown 38.5 percent, according to MessageLabs, so far this year.
''The volume of spam now facing computer users every day has now far surpassed the point of being a nuisance and is now causing significant productivity losses and IT costs at businesses across the world,'' says Mark Sunner, chief technology officer at MessageLabs.
And the percentage of spam containing malware or a virus is on the increase, as well.
MessageLabs analysts found that in July one in 166 emails contained a virus. Bugbear.b, which first appeared in June, spread widely throughout July via email. Several older viruses, such as Sobig, Klez and Yaha, also continued to spread via email last month.
''The lines between virus and spam are becoming increasingly blurred,'' says Sunner. ''In the past, virus writing was just about malicious intent, but the new breed of virus writers clearly have monetary objectives as well.''
Sunner also reports that they are watching a new trend -- spam increasingly is containing back-door trojan attachments. The trojans, once they're inside a corporate network, can be used to create an open-proxy, which lets spammers use the machine to send out even more spam.
''In the past, backdoor-trojans were typically sent by virus makers and distributed through some of the sophisticated mass-mailing techniques contained within viruses themselves,'' explains Sunner. ''Recently, we have started tracking a growing convergence between the techniques of the virus makers and spammers. It is becoming clear that spammers are now adopting aggressive, determined techniques to sustain their ability to spam and outsmart some of the outdated solutions being used to fight them.''
MessageLabs reports that today nearly 60 percent to 70 percent of spam is sent through hijacked open-proxy computers.