2025-02-13
In a recent post on BleepingComputer, hackers have been exploiting a fake Telegram captcha page that instructs users to press the Windows Key + R combination to open the RUN dialog and execute a malicious PowerShell script. This script claims to “verify” the user’s humanity, but in reality, it compromises the system. This article explores how to mitigate such threats by disabling or restricting PowerShell and Windows shortcut keys.
Disabling Windows Key Shortcuts
To prevent the use of Win+R and other Windows key shortcuts, you can use Group Policy or modify the Windows Registry.
Using Group Policy:
1. Open the Group Policy Editor (`gpedit.msc`).
2. Navigate to:
User Configuration > Administrative Templates > Windows Components > File Explorer.
3. In the right pane, locate and double-click on Turn off Windows Key hotkeys.
4. Enable the policy and apply the changes.
Using Registry Editor:
1. Open the Registry Editor (`regedit`).
2. Navigate to:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer.
- Create a new DWORD (32-bit) Value named NoWinKeys.
- Set its value to 1 to disable all Windows key shortcuts.
Restricting PowerShell Execution
To mitigate risks associated with malicious PowerShell scripts, consider the following:
1. Disable PowerShell Completely:
- Open Group Policy Editor (
gpedit.msc). - Navigate to:
Computer Configuration > Administrative Templates > Windows Components > Windows PowerShell. - Enable Turn off PowerShell Execution.
2. Allow Only Signed Scripts:
- Open PowerShell as Administrator.
- Run the following command to set the execution policy:
Set-ExecutionPolicy AllSigned
- This ensures only signed scripts can run.
Using Microsoft PowerToys for Granular Control
Microsoft PowerToys provides a Keyboard Manager utility that allows you to remap specific keys. For example, you can remap Win+R to a harmless key combination while leaving other shortcuts intact.
- Download Microsoft PowerToys: https://lnkd.in/drCDR_zm
- Use the Keyboard Manager to remap Win+R to another key or disable it entirely.
What Undercode Say
In the ever-evolving landscape of cybersecurity, staying vigilant against social engineering attacks is crucial. The fake Telegram captcha scam highlights how attackers exploit user trust and system functionalities like PowerShell and Windows shortcuts. By disabling or restricting these features, you can significantly reduce the attack surface.
For Linux users, similar precautions can be taken by restricting shell access and using tools like AppArmor or SELinux to enforce strict execution policies. For example:
sudo apt-get install apparmor-utils sudo aa-enforce /path/to/profile
Additionally, always verify the integrity of scripts before execution using checksums:
sha256sum script.sh
For Windows, consider using Windows Defender Application Control (WDAC) to enforce script signing policies. Regularly update your systems and educate users about phishing and social engineering tactics.
For further reading, check out the original BleepingComputer article: https://lnkd.in/de5H8ugJ and The Hacker News post: https://lnkd.in/dsZX2-WJ. Stay safe, and always question the legitimacy of unexpected prompts or instructions.
References:
Hackers Feeds, Undercode AI
