I accidentally dropped a two-button-side mouse, and the right-side button now seems permanently held down. The cursor still moves, but normal clicks are ignored or behave strangely. When I connect the mouse to another computer, it has the same problem. After reconnecting my original mouse to the first computer, that mouse also stops working, making it seem like the first mouse somehow infected the second one. I currently have to restart the computer to get things working again. What could be causing this, and how can I safely troubleshoot it?
3 Answers
This is almost certainly physical damage, not malware. A broken or shorted button circuit can make the mouse report that the button is constantly pressed. Unplug the damaged mouse and stop using it, since a serious USB fault could potentially affect the computer's USB controller.
One mouse cannot normally infect another. Try the second mouse in a different USB port, preferably one connected through a separate controller, and test a USB flash drive in the original port. Also test the mouse on another computer. If multiple devices fail on one port, the port or USB controller may have been affected.
Disconnect the dropped mouse, shut the computer down completely, and then start it again before testing a known-good mouse. If the good mouse still fails only on that computer or port, check Device Manager and drivers, but hardware damage is more likely than a software infection. Avoid repeatedly reconnecting the faulty mouse.
Firmware attacks are possible with some advanced peripherals, but they would be very unusual here. The timing and the dropped mouse point much more strongly to a damaged switch, cable, or USB circuit.