My logwatch reported this in this mornings report:

--------------------- Kernel Begin ------------------------

WARNING: Kernel Errors Present usb 3-1: can't read configurations, error -71 ...: 1 Time(s) usb 3-1: can't set config #1, error -71 ...: 8 Time(s) usb 3-1: can't set config #1, error -84 ...: 66 Time(s) usb 3-1: device descriptor read/all, error -71 ...: 3 Time(s) usb 3-1: device descriptor read/all, error -84 ...: 1 Time(s) usb 3-1: device not accepting address 120, error -71 ...: 1 Time(s) usb 3-1: device not accepting address 122, error -71 ...: 1 Time(s) usb 3-1: device not accepting address 14, error -71 ...: 1 Time(s) usb 3-1: device not accepting address 21, error -71 ...: 1 Time(s) usb 3-1: device not accepting address 39, error -71 ...: 1 Time(s) usb 3-1: device not accepting address 50, error -71 ...: 1 Time(s) usb 3-1: device not accepting address 51, error -71 ...: 1 Time(s) usb 3-1: device not accepting address 57, error -71 ...: 1 Time(s) usb 3-1: device not accepting address 58, error -71 ...: 1 Time(s) usb 3-1: device not accepting address 68, error -71 ...: 1 Time(s) usb 3-1: device not accepting address 7, error -71 ...: 1 Time(s) usb 3-1: device not accepting address 78, error -71 ...: 1 Time(s) usb 3-1: string descriptor 0 read error: -71 ...: 2 Time(s)

---------------------- Kernel End -------------------------

I have never seen this sort of thing before. The reporting host is my desktop PC and the office was closed yesterday so I cannot see anyone pushing things in or out of any of the usb ports.

I had a persistent penetration attempt yesterday as well. Could the two be related?