Is this some spyware doing its work?

I am having problems with my internet connection these days.
A couple of times a day, my internet connection just drops.
I am getting suspicious now that the firewall blocks all, based on a tremendous amount of requests from the inside on all sorts op IP adresses. In the firewall logs I find long lists like this

13/04/2010 22:47 --- Exceed MAX incomplete, sent TCP RST --- nnn.nn.nn.22:3990 --- =>
13/04/2010 22:47 --- Exceed MAX incomplete, sent TCP RST --- nnn.nn.nn.22:3986 --- =>
13/04/2010 22:47 --- Exceed MAX incomplete, sent TCP RST --- nnn.nn.nn.11:1592 --- =>
13/04/2010 22:47 --- Exceed MAX incomplete, sent TCP RST --- nnn.nn.nn.11:1591 --- =>
13/04/2010 22:47 --- Exceed MAX incomplete, sent TCP RST --- nnn.nn.nn.11:1590 --- =>
13/04/2010 22:47 --- Exceed MAX incomplete, sent TCP RST --- nnn.nn.nn.11:1586 --- =>

first IP adres is the source computer, second IP adres is the target, after the "=>" I put the target domain, which I derived using tracert.
I think that the target domains are very suspicious.
Anyone an idea what this could be?
Some computers have skype chat, all computers have kaspersky. I don't have a clue on how to interprete this behaviour, and if it is bad, how to remove it

Thanks for your help

LVL 61
Gertone (Geert Bormans)Information ArchitectAsked:
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Not sure, but I'd run Malewarebytes
Def sounds like some bad traffic, maybe some P2P action inside your network (multiple pc's in network?).  I would also load up Pheonix Labs PeerGuardian on the local machine to monitor outgoing TCP/IP requests.
Hi Gertone,
What make+model of router?
How many machines behind router?
When connection drops, above firewall logs coincide with drop, or logging occurs at random times of day?

>Router may not be able to handle "workload"?
>Possible DOS?
>Spyware as you suspect?
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Gertone (Geert Bormans)Information ArchitectAuthor Commented:
Zywall 5 from Zyxell
zywall goes directly to server
and via a switch to a bunch of laptops, sometimes 2, often 3

above firewall logs coincide with drops
it feels as if the zywall starts blocking all trafic when it gets a huge amount of these requests in a short period of time.
The trigger though is weird since traffic comes from all machines, server included, at exactly the same time,
so even if it is a timed execution,  clock time is not exactly the same on all computers,
as if there is an external trigger for all machines

server is win 2003, laptops are XP Prof, service pack 3
Gertone (Geert Bormans)Information ArchitectAuthor Commented:
well and yes, I was thinking about a DOS, but from the inside out

this is home office setting, so no gameplay, only business, no P2P stuff other than skype, no MS messenger
Possibly, or some backdoor bot/botnet junk causing this.
Wouldn't rule out the router acting up either, or due to spyware, its being flooded and drops.

Unfortunately, Not to informed on something like this regarding those logs :(

But no harm to scan those systems as mentioned with Malwarebytes

>>Scan them with Hitmanpro first as if there is a patched system file, Hitmanpro will try and replace it

Post logfiles from Mbam if anything detected and write down anything which Hitmanpro detects.

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In addition to the other great suggestions posted; if they all fail, try creating a bootable antivirus CD. If that doesn't fix it, then you've got some serious problems. It's always good to keep on hand at anytime: 
What I like is that there are just some pesky items that can't be removed while in Windows. I run from a bootable source first, then go into Windows and see what's left over and then deal with it after. The bootable CD sometimes will take care of 80-100% of the infected items; making it that much easier. Best of luck to you.
Gertone (Geert Bormans)Information ArchitectAuthor Commented:
Thanks guys for the helpfull hints.
At the end of the day it turned out that the modem was malfunctioning and since that blocked the router, skype went crazy on the computers behind the firewall. But I got some interesting hints for finding malware, which I used.
Sorry for closing this so late, but it took me some time to figure all out
Not to worry. Glad that you got it sorted :)
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