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    Invelos Forums->General: General Discussion Page: 1  Previous   Next
question on internet security, firewall.
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DVD Profiler Unlimited RegistrantStar Contributorwhispering
On ne passe pas!
Registered: March 13, 2007
Finland Posts: 1,380
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Wondering if anybody could tell me if this is something i should care about.

My firewall has reported about 400 alerts in the past few hours. Most were something like "Inbound TCP connection attempt" (small threat so only shows on the log), then there were some serious threats: "Fin Scan" and "nmap TCP scan".

Should i like, care, about that? The firewall has blocked them, but if it didnt, i woudnt really know. Just got 50 more alerts while typing this message

The reason why i'm asking, is cause i've never had so many.
 Last edited: by whispering
DVD Profiler Desktop and Mobile RegistrantStar ContributorSkywatcher
Registered: Feb. 7, 2002
Registered: March 13, 2007
Portugal Posts: 315
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Some user (probabaly a customer of your ISP, but not necessarily) is doing a port scan to your computer, either to all ports or some selected ones only.

99% sure it's what is called a range scan, i.e., the guy responsible fo it just selects a range of IP addresses (in this case, belonging to your ISP) and lets the scanning software do port scans to all computers inside that address range trying to find one that's vulnerable/unprotected.

They were quite popular a few years ago, but nowadays ISPs usually have software running in their network that detects that kind of behaviour from a costumer and he'll probably get a "friendly" email warning.

If your firewall detected it, it's a good thing, it means it's working and protecting you against it 

Edit: If it's getting annoying, just take your connection down and then back up after a few minutes in order to to try to get a different IP address (hopefully outside the range the guy is scanning)
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 Last edited: by Skywatcher
DVD Profiler Unlimited RegistrantStar Contributorwhispering
On ne passe pas!
Registered: March 13, 2007
Finland Posts: 1,380
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^^ Thank you very much for the info

...so far 1000 alerts. I tryed closing my router for 20 seconds, ill try to close it again for few minutes.
DVD Profiler Unlimited RegistrantStar Contributornorthbloke
Registered: March 15, 2007
Reputation: High Rating
United Kingdom Posts: 5,459
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Remember to completely close your connection down.
In order to get a new IP address I have to actually unplug my cable modem from the mains and wait a minute or two before plugging it back in.
Obviously your connection may be different 
DVD Profiler Unlimited Registrantkatharsis
Registered: March 13, 2007
United States Posts: 93
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Skywatcher has pretty much explained whats happening already...

There are some software firewalls that let you see what IP address the scan is coming from.  If you can check on it, see if its the same address over and over, you can then either block it or even try to contact your ISP and make them aware of this, I am sure if its one of their customers they'll take care of it real quick!
You also mentioned using a router, you can block either certain IPs or check on the ports that are open  and you might be vulnerable to.  Close all the ones you dont need
If you have DSL or need to sign in to access the internet, just restart the connection or shutdown modem and router.  Certain cable connections might be more tricky (if you dont have a static ip address) sometimes just shutting off  the modem or resetting it, doesnt do the trick, because your ISP will take care of it automatically, if its getting to annoying you can call them up and ask for an IP change as well.
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