Open-Source Skype - how to get a users IP address [NOTE: This exploit is currently being investigated by Microsoft/Skype, so act quick - also, I'm not sure who first found this out, but ALL CREDIT goes to them for finding it - I'm just going to try and make it a bit easier to understand, since it's not in very good English and some people don't understand it.] This is the original post [http://pastebin.com/rBu4jDm8]

NOTE::: READ EVERYTHING ON STEP TWO FIRST BEFORE YOU CONTINUE, THERE ARE MULTIPLE WAYS TO DO IT.
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First, go to [https://github.com/downloads/skypeopensource/skypeopensource/skype55.zip] to download Open-Source Skype 5.5 (direct download).
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Second, Go to 'regedit' (Start>SearchBar>regedit>enter) (this post may help you out: https://github.com/skypeopensource/skypeopensource/wiki/skype-3.x-4.x-5.x-enable-logging) then go to: 'HKEY_CURRENT_USER>Software>Skype>Phone>UI>General' and make sure that 'Language' is set to 'en' (double click to change) then you can either:

1) 'RightClick>New>String' and set 'value name' to 'Logging' and set 'value data' to 'SkypeDebug2003' - then 'RightClick>new>string' and set 'value name' to 'Logging2' and set 'value data' to 'on' OR you can do it the easy way:

2) Go to [http://developer.skype.com/SkypeGarage/LogFile] and follow the instructions (including downloading the 'logging-on-off.zip file that is provided, in direct download - this just means that once it's downloaded, you simply double click on 'logging-on' and it sets all of the above on automatically, meaning you don't need to mess around with RegEdit and potentially mess something up, then once your done, simply click 'logging-off' and it will set everything to off, until the next time).
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Thirdly, open the file called 'Skype55' (that you downloaded earlier) then run 'Step5' (NOTE: BEFORE YOU DO THIS, YOU MUST HAVE 'LOGGING-ON' TURNED ON FIRST, ONCE YOU HAVE IT TURNED ON, THEN RUN 'STEP5') then Sign On, and click 'Add contact' > once you have the username of the victim there, just click on his/her name, to open their VCard (you don't need to actually send the request for this to work).
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Fourth, (once you have the 'logging-on' file running [got everything set up in 'RegEdit'] and have opened 'Step5' and opened the users 'VCard') just close all 'Skype' tabs, then double click on 'Logging-off' to turn the logging in 'RegEdit' off, then go to your 'Skype data directory' (Computer>C:[assuming this is where you store your files, and assuming it's on 'Windows 7']>Users>USERNAME>AppData>Roaming>Skype>Then find the victims 'Skype' name and open their file, and voila.
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Step 5, (more like a bonus step) take a look in the victims log file, their record will be like this for their real user ip: -r195.100.213.25:31101 and like this for the user internal network card ip:             -l172.10.5.17 [NOTE: These IP's aren't mine] - (21:16:45.818 T # 3668 PresenceManager: aїљ noticing skypetestuser1 0x3e54a539a91a19fc-s-s65.55.223.23 :40013-r195 .100.213.25:31101-l172 .10.5.17:22960 23d23109 82f328ff).
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Step 6, (bonus step) Catch the 'user' via the 'Whois' service [http://www.ip-adress.com/reverse_ip/] < just paste the IP into there, then hit 'enter' - this will give you info about the user, such as Location, Internet provider and internal user ip-address.

And we're done! :-D

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(ANOTHER BONUS)
For anyone interested, here is the 'Perl' script:
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#!perl

$LOGFILE="debug-20120420-2257.log";
$SKYPENAME="skypetestuser1";

open(RD,$LOGFILE);
open(WR,">_ip_logger.txt");
while(<RD>){ chomp;
 $line=$_;

 if( ($line=~ /PresenceManager:/) and ($line=~ /noticing/) ){
  $line=~ /-r(\d+.\d+.\d+.\d+)/;
  $ip=$1;

  print WR $line."\n";
  print WR "IP: $ip\n";

  if ($line=~ /$SKYPENAME/){
   print $line."\n";
   print "${SKYPENAME} IP: $ip\n";
  };
 };

};
close(RD);
close(WR);
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---- Wuulfite (PS- Come at me broski).