[SpamCop-List] investment spam

[RandallW]

I receive little floods of investment spam, for HYIP programs.  Many of the 
spamvertised sites don't seem to selling anything, as if the spam is just a 
joe job.

The spam comes in little surges; one arrives, then another about 3 min. 
later, then another 3 min. for the next.  Is it more likely, or less, the 
spam is sent from infected machines?

Example of this spam:

http://www.spamcop.net/sc?id=z919835977z05598ec0f94abc1c736a216c01fcd68az