All, I would immediately stop downloading clients from mega.co links, and only download from versions Jeanluc posts on info.crypto.org or on forums.nxtcrypto.org. There should also be a mirror site on
www.nxtcrypto.org.
If your funds were stolen and you have a 30+ long passphrase consisting of upper/lower/number characters and is not anything in print or spoken, then you have a keylogger on your PC that saw your password. One was recently made and released as some IM app that stole funds.
Method to freeze funds into a new acct. (You will not be able to forge with these funds)1. Boot to linux live CD. Use one a few months old. The live CD must have java jre 1.7
2. install latest client from forums.nxtcrypto.org/client.zip
3. write your new complex passphrase on a piece of paper
4. unlock the client with passphrase.
5. write down the new account number
6. lock it and unlock again.
7. verify account number.
8. do 6 & 7 again once more to verify.
9. write long passphrase on a piece of paper. (paper wallet)
10. open old account, send funds to new account
11. close old account, open new account
12. wait for a few confirmations of the transfer to the new account
discussion of this method here:
https://forums.nxtcrypto.org/viewtopic.php?f=17&t=267