I've read about malware infecting computers from an infected USB drive so I got a bit worried.
I recently used one of my flash drives to give some files to a co-worker. He plugged the flash drive in, transferred the files to his computer and and gave the drive back a minute later.
Would it be possible for my computer to be infected with malware after using the USB drive again, assuming his computer was infected?
Possible but not as easy as it used to be because wndows won't autorun files from a usb disk like it used to on older versions, but if there are any extra files on it don't click on them unless you know why they are there. You can always scan the drive or just reformat it if worried.