LogChekker searches the log files that are sent from your router to your e-mail client, It presents results in Ip address, port number and the count from the Ip address on that specific port.

You can then do a quick search on any ip address to see if there are more incidents on other ports from the selected ip address. If more incidents was found you can then by using the copy/paste button copy the ip address to the search box and search again this time you will be presented by ip address port number and the number of times the ip address was
found on different port numbers.

And if you feel that there are no accidental attempts you can then go to the menu Edit and choose Options where you can turn on full text search(sorted full text search). After the new search is finished, you can then see by looking at the
time stamps (date, time of day). And if you still fell that there are no accidental attempts you then have the option to save the result in either .txt or .doc format and send a email to either your own ISP or to the ISP of the person who has by your own opinion attempted to do some harm to your machine.

To find the persons ISP you can just select one of the ip addresses and push the IP button and the program will try and do a reverse DNS and a Whois lookup and then you will be able to see what ISP the person was using.
You can check it out here http://logchekker.net/howToUse.htm
Or download the Lite version here: http://logchekker.net/LogChekkerLite/LogChekkerLiteSetup.exe
And if you need the jre as well:
http://logchekker.net/LogChekkerLite/LogChekkerLiteAndJRE1.5.0.6.zip