Some discussion on that here:
http://discussions.apple.com/thread.jspa?threadID=1485315
Couldn't really find a definitive answer, but it does look interesting, at the least, and concerning at the most.
The fact that sudo has been modified is the troubling. I want to say, being a Mac, that these are benign, but I'm really leaning toward something else. Are you up-to-date on the handful of trojans that you can be tricked into installing on your computer? If not, I'm sure there are more than enough threads here to cover the most prolific. There are some scanning tools out there that can detect one or more of these trojans, which I highly recommend you run.
It may not hurt, if you're versed in the Terminal, to try to compare digests between the BOM and the actual executable itself (I would definitely try it with the "sudo" entry, that's for sure) to see if there's a discrepancy. This would mean that somehow, somewhere along the way, the "sudo" executable was modified by something, either intentionally, unintentionally, maliciously or accidentally. How to do that is outline in the Apple Discussion linked above.