To pull this a bit more into Perl land:

I haven't seen any such traffic in the web logs of my webserver. But I recommend Net::Pcap to monitor your network traffic from Perl. If you're convinced that it is TCP or even HTTP traffic, you can go to more specialized modules like my Sniffer::Connection or Sniffer::HTTP, or do post-mortem analysis through Net::TcpDumpLog or libpcap itself.