How to Detect and Stop Unauthorized Remote Access on Windows PC

Is your mouse pointer waltzing across the screen with the panache of a ghostly marionette, programs launching and closing as if your PC has developed a mind of its own? Or perhaps new user accounts have appeared mysteriously, and your once-pristine desktop now sports a lineup of unfamiliar programs. If any of this sounds familiar, you might be harboring a digital intruder—someone could be remotely accessing your computer without your knowledge. Let’s peel back the virtual curtain and find out not just what’s going on but how you can reclaim command of your own machine.

The Curious Case of Remote Access: What’s Really Happening?​

Picture this: it’s midnight, you’re sound asleep, and somewhere, perhaps across town or continents away, someone is interacting with your PC as though seated at your desk. Welcome to the world of remote access—where boundaries blur, and your digital space can be an open house if you’re not careful.
At the heart of legitimate remote access lies convenience: IT support, remote work, file retrieval. But in the parallel universe of cyber-threats, remote access is the front door left ajar for hackers and mischievous insiders. Knowing whether someone is tucked away in your system remotely is a skill every Windows user should hone.

First Line of Defense: Are the Gates Open?​

Your first stop on this voyage: Windows’ own settings. On both Windows 10 and Windows 11, Microsoft has neatly stashed away the keys to remote access within the System settings.

• Tap Windows Key + I to open Settings.
• Navigate to System then scroll to Remote Desktop.
• Inside Remote Desktop, click the arrow next to Remote Desktop users.

Voilà! You’re now staring at the VIP guestlist—the users allowed to remotely access your machine. If you see unfamiliar names, it’s a red flag. You can trim this list with ruthless efficiency, removing anyone you don’t recognize or trust.
And for the ultimate power move: simply toggle Remote Desktop off. This one elegant flick locks your house to outsiders (well, at least as far as Remote Desktop Protocol, or RDP, is concerned).

Tell-Tale Signs Your PC Has Gone Poltergeist​

Let’s say you don’t spot suspicious users in the guestlist. Before you settle back into comfort, remember: hackers are a creative bunch. So, let’s look for a spookier set of clues.

1. New Programs Suddenly Appear​

If new apps spring up like digital weeds or old favorites mysteriously vanish, it’s time for a second look. Hackers, after all, often install software to give themselves persistent access, or worse, to capture your keystrokes and files.

2. New User Accounts Are Born​

Criminals are rarely content with just using your account—they often create their own, hoping to blend right in with legitimate users. Check the user list by going to Control Panel > User Accounts > Manage another account.

3. Phantom Mouse Movements​

Few things are creepier than watching your mouse pointer move on its own. If you witness windows opening or closing without your command, or cursors drifting with a mind of their own, a remote presence could be at the controls.

4. Windows Event Viewer: The Digital Diary​

For those who love a good detective story, Windows Event Viewer is your magnifying glass. Hit Win + R, type eventvwr.msc, and press Enter. In the logs (especially under Security), hunt down Event ID 4624—that’s a logon record. Troublingly, Logon type 10 corresponds with remote logins using RDP. If you see these appearing when you weren’t actively connecting, it’s time for action.

Sound the Alarm! What to Do if You’re Under Siege​

Finding evidence of remote access is like smelling smoke: it’s time to move quickly to prevent a full-blown digital inferno.

Disable Remote Access (With Feeling)​

Invoke the classic Run dialog (Win + R), type SystemPropertiesRemote.exe, and press Enter. Ensure "Don’t allow remote connections to this computer" is selected. Remember to enforce this in Windows Settings as well, under System > Remote Desktop. This slams the Remote Desktop door shut.

Evict Unwanted Programs​

Peruse your Programs list in Settings > Apps > Installed Apps or Control Panel > Programs and Features. Uninstall anything that looks odd or that you definitely didn’t install. Be merciless; if in doubt, look it up or consult your IT wizard friend.

Unleash Your Antivirus​

Hackers rarely announce their presence with trumpets; sometimes, they leave stealthy malware behind. Run a boot-time scan with your antivirus or, if you prefer Microsoft’s homegrown tools, perform an Offline scan with Windows Defender. This scans for threats before Windows boots, giving malware less time to hide.

Monitor Network Traffic Like a Hawk​

Curious about what’s happening under the hood? Network monitoring tools—like Wireshark or the more user-friendly GlassWire—let you inspect which apps are using your bandwidth. If you see excessive network traffic when your machine should be idle, or connections to unusual foreign IP addresses, you might be a target.

Block the Usual Suspects: Firewall Rules​

Certain ports are hot real estate for remote access:

• 3389: Remote Desktop Protocol (RDP)
• 5900: Virtual Network Computing (VNC)
• 5938: TeamViewer
• 6568: AnyDesk
• 8200: GoToMyPC

Use Windows Defender Firewall (search it from the Start menu), and block inbound connections to these ports if you don't use the related services. With these ports shut, most garden-variety remote access attempts will bounce off like flies hitting a windshield.

Who’s There? Checking Active Remote Sessions​

Now, let’s say you’re really curious. Is anyone actively snooping around right now? Dive into the Remote Desktop Services Manager—if you have the right version of Windows (typically Windows Pro or Enterprise). Open it and jump to the Users tab for a list of who’s in and out. The Sessions tab also offers deeper detail including usernames, session IDs, and connection types.
If you don’t have access to the Remote Desktop Services Manager, the classic Task Manager (Ctrl + Shift + Esc) also gives hints under the Users tab, showing active accounts logged in.

Workplace Paranoia: Is Your Computer Being Monitored?​

Maybe you’re not worried about criminals but about corporate snooping. Employers can leverage enterprise tools to monitor computers well beyond basic remote access: think full-blown surveillance, screen recordings, and even keystroke logging. If your workstation is company-issued, operate with the baseline assumption that everything you do could be observed. Ethics and legality aside, it’s always smart to double-check your employer’s privacy policies.

The Slippery Slope: The Difference Between Remote Access and “Hacked”​

It’s easy to conflate unauthorized remote access with being “hacked.” While both spells bad news for privacy, sometimes unwanted connections are about opportunistic snooping or poorly configured settings, not a full-blown malware infestation.
If you spot suspicious remote connections but not many other signs, locking down your remote access settings may be all you need. But if you’re seeing multiple warning signs—rampant malware, system slowdowns, blackmail pop-ups—prepare for a deeper cleaning process. Professional help might be in order.

Advanced Snooping: Checking for Hidden Software and Backdoors​

The truly sneaky intruder doesn’t use built-in Remote Desktop—they deploy sophisticated remote-control software disguised to look official or even invisible. Here’s how to sniff them out:

• Review Running Processes: Open Task Manager or, for the brave, dive into Process Explorer (a Microsoft Sysinternals tool). Google anything unfamiliar you spot snacking on your CPU cycles or running in the background.
• Inspect Startup Items: Check Startup Apps under Task Manager or use third-party tools like Autoruns. Malware loves to hide in auto-run entries.
• Audit Installed Programs: Peruse your installed apps for anything like TeamViewer, AnyDesk, or GoToMyPC that you didn’t install. Remove and investigate as necessary.
• Check Your Router: If someone has access to your network at the router level or has set up VPN tunnels, they could intercept your traffic remotely. Log in to your router and review connected devices for anything odd.

Extreme Measures: When in Doubt, Wipe Out​

If all else fails—if your computer starts acting like it’s auditioning for a horror movie, if malware keeps coming back, if your vital data is at stake—there’s always the nuclear option. Backup your files, format your drive, and perform a clean install of Windows. It might sound drastic, but sometimes it’s the only shot at peace of mind.

Prevention: Remote Access Hygiene​

As with most tech headaches, prevention is better than finding yourself in the role of amateur computer security detective. Here’s a digestible checklist:

• Turn off Remote Desktop if you don't use it.
• Use strong, unique passwords.
• Never share your credentials—or write them on a sticky note stuck to your monitor.
• Keep your system and antivirus up to date.
• Use Two-Factor Authentication (2FA) wherever possible.
• Be wary of emails and links; phishing can give attackers remote access faster than you can say “You’ve Won a Free iPhone!”

Peering into the Future: Evolving Threats​

In a world of hybrid work and ever-expanding digital services, remote access will only grow—so too will the ingenuity of crooks looking to exploit it. Expect more attacks targeting alternative remote desktop protocols, social engineering attempts, and even AI-powered hacking tools.
On the flip side, expect security to get smarter, too. Windows is constantly updating with new features to detect and block unauthorized remote connections, and better alerts are coming for regular users. Meanwhile, IT pros will rely on more sophisticated network and endpoint monitoring to stay one step ahead.

One Last Word: Trust, but Verify​

The internet is a marvelous place, but it’s filled with more villains than a late-night superhero cartoon marathon. A bit of vigilance goes a long way. Make log-checking, user audits, and network monitoring part of your regular digital hygiene.
If you suspect someone has been virtually squatting in your desktop real estate, don’t just hope for the best. Investigate, secure your settings, kick out unwanted guests, and lock the door. With the right mix of skepticism and technical savvy, you’ll keep your digital life yours—and only yours.

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Source: The Windows Club How to check if someone is remotely accessing your computer