"IT guy" Jrockilla told the Talesfromtechsupport forum that he suspects his bosses e-cigarette was the source of malware. He posts that the malware was hard coded into the device.

He said:

The executive’s system was patched up to date, had anti-virus and up-to-date anti-malware protection. Web logs were scoured and all attempts made to identify the source of the infection were to no avail. Finally, after all traditional means of infection were covered, IT started looking into other possibilities. It finally asked the executive “have there been any changes in your life recently”? The executive answer was, “well yes, I quit smoking two weeks ago and switched to e-cigarettes"...

He added:

...[The] e-cigarette had malware hard coded into the charger and when plugged into a computer’s USB port the malware phoned home and infected the system.
He has not supplied further evidence, but it is the danger corporates face with users plugging unauthorized devices into USB ports for charging.

The thread warns that it might be significant pointing to research by the German researchers SRLabs that USB devices can be made unstoppable.

If you want to investigate what a port is doing, you can use FaceDancer.