This scary incident happened today morning. I started a virtual machine inside my Linux Mint host and shared my USB Wireless device with the machine. The virtual machine's image resided in an external USB hard-disk.Now, when we share some USB device with the virtual machine, that USB device is then not accessible by the host machine. For example, if I share my USB mouse, then it will only work inside the virtual machine and not the host. Anyways, as I was working in my virtual machine. Suddenly, it crashed and stopped working. I closed it forcefully. Then, whenever I tried starting it in VirtualBox, it said VD: error VERR_FILE_NOT_FOUND opening image file.... I realized that somehow my external USB hard-disk had got disconnected and since the virtual machine's image lied in that hard-disk, it was showing this error. Big Deal. I just restarted my machine. Guess what. When I login into my account, no USB port is working. My external USB hard-disk is not showing up. My USB wireless device is also not working. And even my mouse and keyboard were not working. Everything was powered up, but not working. Luckily, my ethernet port was working and I had Synergy up and running, and I also had ssh. I just used my laptop to access my Linux Mint and tried a few reboots. Nothing was working. All the ports seemed to be working right before the login but as soon as I logged in, everything just stopped working. After a few reboots and freaking out, I opened my virtualbox and deleted that virtual machine's image. And then rebooted. This time, everything was back to normal. So, my guess is that VirtualBox had somehow hijacked all my USB devices and everytime I was logging in, they were not available to me. Now, can someone tell me: Is my guess right? Was VirtualBox indeed the culprit? All the clues do point in its direction. If it was VBox, then how come it went on to hijack/reserve all USB devices in case of failure. I had only shared one USB device with it i.e. my USB wireless device. Is this a bug? Did my virtual machine have some virus, and it did something nasty? How come the USB devices are reserved right after login even when VirtualBox is not running? How to deal with such cases in future? Any other light on the matter? 
USB not working : USB Ports Hijacked/Reserved Permanently by VirtualBox
usb;virtualbox;virtual machine;debugging