You have just fallen for a BadUSB trap.
This USB stick is part of an internal security exercise. It was placed by our IT team to test the vigilance of our employees. The IT department has been notified.
The stick has not stolen any data or installed malware, but it has proven that a simple item found at your workstation can pose a serious threat. In a real attack, this stick would have acted as a keyboard and executed malicious commands to compromise our network.
Here is what to do now: