logwatch reports "connection attempts using mod_proxy"

[Matt Morgan]

The httpd section of my logwatch reports:

Connection attempts using mod_proxy:
   141.155.241.10 -> 1.3.3.7:1337 : 2 Time(s)

I have no idea what this means, and the message is resistant to my
attempts to google it (or find it in the list archives). Any hints?
Neither IP address bears any relation to the server reporting the
connection attempt.

I can't help noticing that the port (1337) spells "leet," i.e.,
"elite," in script-kiddie nerdspeak. So I'm guessing it's some kind of
bug exploit, but I don't know this one.

Thanks,
Matt