Intrusion alerts??

Question

I have received six intrusion alerts where someone has tried to get into my system today. I've never received a single one before. So far everyone of them has been blocked, as far as I know. I traced the last one to an Internet cafe in China. How come I am getting so many? Does it have anything to do with me being on Yahoo! more now that I am doing this answers thing? Do I need to be worried

Answer 1

There's a possibility that you have a vulnerability in your system, most likely in the form of a port accepting connections that shouldn't be. If someone is conducting a port scan of your system and finds a vulnerable port, they'll be sure to tell their friends or use other systems to try and exploit it.

Go to http://www.grc.com and conduct a quick scan to determine if your computer is vulnerable. If you don't have any susceptible ports, you should be fine. If you're at work, I'd contact your network admin immediately to cut it off; if not, I'd be sure that you have a personal firewall, be it hardware or software, up and running to prevent any intrusions so you KNOW they are blocked.

If your scan is clean, download anti-spyware programs such as SpyBot S&D and AdAware. These are also capable of picking up trojans, so they will cover everything that might be attacking you.

Answer 2

Limit your exposure to the outside world by blocking incomming connections.

Start > Settings > Control Panel > Network Connections
Right click on "Local Area Network" And go to "Properties", In the scroll box, Click on "Internet Protocol (IP/TCP)" and then click on the "Properties" button, In the new window, Click on the "Advanced.." button, Then in the other new window go to the "Options" tab, Click on "TCP/IP Filtering" and hit "Properties", Check off "Enable TCP/IP filtering (All adapters)" next In the Above "TCP Ports" Click on the Radio button "Permit Only" and then add in the ports that you want people to be able to access... If you're running a web server add in 80, If you're running an FTP server add in 21... And so on... Then hit "OK" And close all the other windows, And reboot when it asks you too.

This way you can close the ports that you do not need to be open to the outside world. An alternative to this tweak could be running a firewall or enabling windows built in firewall. Please note that in order for other computers to connect to you, for example sending a file over AOL Instant Messenger or using Windows Messenger to send a file, make sure that the required port is not blocked on your system. Otherwise, nothing will go through. ;-0)

Answer 3

Nothing to worry at all if you have a intrusion detection and personal firewall system installed on your PC.