Ok Remote_Access_ touched on this topic briefly in his (I use the term loosely )

ICQ - the worst thing that ever happened to privacy and anonymity
post on this board but I thought I would try to explain a few other methods for gettin' someone elses IP addy. It maybe helpfull for some newbies - but I doubt any experienced users will learn anything I'm afraid

Ok first of all the easiest way is the /dns command in IRC simply type (in the same place as you would normally type what u want to say) /dns persons nick - in the status window it should now display the persons IP. Ok easy peasy but what if the person don't use IRC?

As mentioned by cshs any program that establishes a p2p (peer to peer) connection will alow you to get that perosns IP addy.

Also, the particular 'vulnerability' you discuss is not limited to ICQ, or even IMs in general, but to anything wherein there is peer-to-peer communication. Anytime someone establishes a connection to your computer, you can find out their IP -- that's how it's supposed to work.
Ok guess I'd better explain what a p2p connection is. This is where your compiuter and the perons computer whom u r chatting to is connected directly without going thru a server. Very few IM's these days use this system as it is safer to go thru there server thus hiding ur IP. However with msn (and prolly the others tho I never use them) even tho ur msgs pass thru their server whenever u initiate a file transfer u r then connected p2p. So simply get the perosn to accept a file - it can be anything at all but ur usually better offering them a .jpg/.txt/.gif etc as many peps are not comfortable with accepting .exe/.pif/etc

Once the file transfer has started open ur Dos-prompt and type "netstat -n" without the quotation marks - u should then see 2 columns of numbers. The left hand column is ur ip (u'll notice they're all the same only the port numbers at the end differ) and the right hand column is the ip's ur connected to.

Now it can be confussing figuring out which ip is actually the one belonging to the person u want esp if u have alot of connections running but thru a process of elliminaion u should be able to find it. Just look at the port numbers and rule of the ones you know, 80 web-browser, 21 ftp etc

Ok but what i u cant get them to accept any files from u? Well then u gotta start using 3rd party progs the one I'll concentrate on is ass-snifer The use of which I'll not go into as its pretty self explanitory. Basically what it does is generates an addy like http://106758390 which when someone clicks on its sends their ip to u via ass-sniffer (I have no idea how this works, if anyone does I would be very intrested to know ) But after using it for a while myself I came across another prob peps became wary of going to such an odd looking url. An easy way round this is to set up a web-redirect on a free server like http://www.geocities.com/urnick which points at the ass-sniffer addy.

The last way is only to be used when daling with a complete novice who won't accept file transfers - simply open a new .txt document and type in netstat -n close it and change the file exstension to .bat and email it to them (some peps will accept files thru email as hotmail does a virus check on every attatchment sent thru there email system and will not let u download the file if a virus is found) Now that they have seen it is clean of virii tell them to run it and quote u the top number from the left hand column - u can bullshit them with some story that certain versions of windows needs a patch against the imanidiot virus and running the .bat file will show them there windows version number or something

right hope thats of some use to somebody

VAL`