A new uTorrent version was released two days ago which fixes a remote exploit which was discovered earlier on. Hackers were able to manipulate torrent files which would cause a buffer overflow at the targets computer which would make it possible to execute code on it.

Just replace the new file with the old uTorrent file and everything should work as usual afterwards. The list of changes for uTorrent 1.6.1

• Feature: Select upload/download speed for a torrent through the right-click menu
• Feature: Added encryption box to speed guide- Change: Don’t check as many pieces at the same time.
• Change: Misc WebUI changes.
• Change: Switch to JSON for webinterface
• Fix: Problem with category list in the gui when updated from the webui
• Fix: WebUI not clearing state between requests.
• Fix: Redirect also index.html to guest.html
• Fix: Added On Now shows the time it’s added, not loaded.
• Fix: JSON uses ” instead of ‘
• Fix: (a) Upnp fix
• Fix: Show pause icon when checking is paused.
• Fix: Fixed problems with XML parser
• Fix: Don’t allow two message boxes to be shown in the RSS window
• Fix: Changed some window titles
• Fix: Fix malformed .torrent exploit
• Fix: Boss key field is now larger

source: TorrentFreak