Despite blacklists, email filters and even governmental efforts like the Can Spam law, the flood of unsolicited commercial email comes coming. And several analysts point to the convergence of spammers and virus writers as the cause.
It used to be that blackhat hackers wrote malicious code to make a name for themselves. They wanted the notoriety and respect in the underground community. Several months ago, however, analysts started to see a dramatic increase in virus writers working to make a buck instead of making a name for themselves.
Because of that malicious marriage of spam and viruses, an increasing number of worms are being let loose in the wild complete with backdoor Trojans and the ability to set up open proxies. Once those are in place, the spammers can take control of the infected machines and use them to send out wave after wave of spam.
Anti-virus experts estimate that the recent MyDoom-A worm compromised 500,000 to 1 million computers -- all with open proxies. And they expect that army of zombie machines will be put to use in the spam community, much as anti-spam experts believe computers infected with the Sobig virus were.
''Just a year ago, it wasn't a major problem,'' says Lavaste. ''There's definitely been a dramatic increase. Today, open proxies generate at least one-third of the spam volume.''
Lavaste adds that they see a lot of spam coming from computers compromised by the Sobig virus and though they haven't seen it yet, they expect to see it start coming from MyDoom infected computers.
Sunner adds that he expects a huge increase because of MyDoom.
''I would suspect to see an increase because of MyDoom since it's so similar to Sobig,'' he explains. ''You now have a whole plethora of machines harvested to send out spam if the author wants... It sticks out like a huge beacon that this is where the spam is coming from.''