Using http as mail spam engine

Mon Nov 5 20:07:13 UTC 2007

    I noticed these entries in my apache log today:

    60.250.66.175 - - [01/Nov/2007:04:41:01 -0600] "CONNECT 
218.32.192.11:25 HTTP/1.0" 200 12439 "-" "-"
    60.250.66.175 - - [01/Nov/2007:04:41:04 -0600] "CONNECT 
61.31.198.50:25 HTTP/1.0" 200 12439 "-" "-"
    60.250.66.175 - - [01/Nov/2007:04:43:28 -0600] "CONNECT 
60.249.125.71:25 HTTP/1.0" 200 12439 "-" "-"
    159.148.97.91 - - [02/Nov/2007:22:01:40 -0600] "CONNECT 
195.175.37.70:8080 HTTP/1.0" 200 14301 "-" "-"
    159.148.97.91 - - [02/Nov/2007:22:01:41 -0600] "CONNECT 
159.148.96.222:80 HTTP/1.0" 200 14301 "-" "-"

    And while the first two are specifically targeting port 25, the 
other two aren't  But more importantly, how is this being done, and how 
do I stop it?  Did I forgot to disable something within Apache somewhere?