While it is imperative to never permit remote access to your computer by unfamiliar parties (or those without a contractual agreement),unfortunately lapses in judgment due occur. One of the initial actions these malicious actors may undertake is to immobilize your keyboard, thereby preventing your intervention to stop them from accessing sensitive information.  In such scenarios, the quickest way to get them off and provide IT professionals with comprehensive forensic data is to disconnect your device from the internet. Alternatively, if this proves impractical, powering off your machine is the next advisable course of action.  Some ways to go about this are:

•  If your machine has an ethernet cable, pull out the cable from your machine.   
• If you are in an environment where you have access to the internet modem or router, go and unplug that to terminate internet connectivity.
•  If you are on a desktop computer, yank out the power cord.
• If you are on a laptop, hold the power button down until the device turns off.

Once you have gotten the threat actor off of your machine, an immediate assessment should be conducted to ascertain any compromised accounts.  Priority should be given to any banking accounts.  Second, any passwords stored in web browsers should promptly be changed with Multi-factor Authentication put in place where possible.  Given the uncertainty surrounding the extent of the threat actor's actions on your system, the most prudent course of action entails rebuilding your computer to eradicate any potential residual threats unbeknownst to you.

Such incidents represent a grave breach of privacy, akin to a home invasion where personal belongings are targeted. Should you find yourself overwhelmed and uncertain about subsequent measures, seeking assistance from an IT professional is advisable. They can adeptly guide you through the process of securing your accounts, eliminating any unauthorized software, and implementing preventative measures for the future.