It's name is
KAzdyLisjm and when I try to list it's contents or delete it, those operations never return a result. It does appear to occupy over 300MB of space though, according to
ls -lh, from the parent directory. Applications like FileZilla or anything that traverses it becomes unusable.
Permissions seem normal:
drwxrwxr-x 2 john john 353M Jun 10 21:44 KAzdyLisjm
I have come across only one instance of this on Stack Overflow but there are no answers.
Update: I have tried booting a live CD and repeating the suggestioins in the comments below but there is no difference. From the livecd, I also ran fsck on /dev/sda1 and it reported the partition as "clean". Running badblocks returned no errors and the smart disk utility bundled with Ubuntu reports nothing with the quick scan. I will run the full scan but unless I update this in the next hour you can assume those tests passed also.