This is likely a weak configuration issue. On the XP PCs I would use a
3rd party firewall (XP firewall is one-way only), disable Remote
Assistance and any unused network protocols. Since your security has
already been comprimised I highly reccomend you change all account
passwords including the Administrator password on all your machines and
check for trojans, viruses, etc. with up to date a/v tools.
I have two Windows XP computers; the first computer with Windows XP Home
Edition SP2 and second computer with Windows XP Professional SP2. Both
computers have no viruses, spyware, etc. found. Strangely when the
first computer gets turned on, it causes lots of traffic on the LinkSys
WRT54GS router and the traffic does not go out on the DSL connection.
Seems like the first computer attacks the LAN connection and not the
Internet connection. When the first computer gets turned off from a
proper shut down of Windows XP, the traffic goes away. When Internet
Explorer 6 SP2 runs on the system, the Internet connection is very slow
including the overall system performance.
On the first computer, the problematic computer, where Norton AntiVirus
2004 exists and always fully updated, Norton AntiVirus 2004 does not
find any virus, trojan, worm, etc. infections. The first computer is
free of viruses based on Norton AntiVirus 2004 full system scans.
Spybot Search and Destroy also runs on the first computer with all
updates installed and Spybot does not find any spyware.
Whatever is occurring on the first computer has not affected (and
infected) the second computer. When the first computer runs Mozilla
Firefox 1.0, there is no additional traffic than there is when the first
is on. There is something in Windows XP Home Edition SP2 causing an
increased traffic when Internet Explorer 6 SP2 runs on the system.
The first system is not always in use and I leave it turned off. The
second system is my primary system and its always in use.
All software has been scrupulously installed on these systems to avoid
spyware, viruses, tracking, etc.