14 DAY TRIAL // The amount of spam has already surpassed alarming levels as practically over 95% of the total email volume circulating represents spam. Also, newer versions of trojans are having the compromised computers send spam through their owners' ISPs. Previously, it was a simple enough thing for ISPs to blacklist the domains used by zombified PCs acting as mail servers or block port 25, the standard port used by SMTP (Simple Mail Transmission Protocol). But when ISPs themselves are generating immense volumes of spam, blacklisting will become impossible.
Zombie systems are computers hi-jacked without owners' knowledge by spammers who then use them to send out billions of unsolicited emails.
Microsoft is taking stand for this situation and what they came up with is somewhat unorthodox compared to the standard spam detection and blocking procedures. The company decided purposely infecting a computer with malicious code.
The company announced it had detected a computer who had been turned into a zombie; it then located the worm generating the attack and moved it to a test computer in order to watch its reaction. The infected machine received 5 million connections from spam operations using the network, causing the computer to attempt to send more than 18 million spam messages during a 20-day period.
The computer was quarantined in order to prevent actually sending the messages, but Microsoft used the information it found about the zombie network to file suit against a series of anonymous defendants.