Create a Watchdog in Windows: Keep Your Cellular APN Correct and Connected

I manage a small fleet of Windows field laptops with built-in cellular modems. They leave the office on the corporate APN and come back months later — usually after a driver update, a Windows feature update, or someone reseating the SIM — quietly sitting on the carrier’s consumer APN instead. The machine happily reports Connected. It even passes traffic. It just cannot reach anything on the corporate network: no VPN, no telemetry, no remote management. You find out from an angry phone call, never from the machine itself. ...

September 29, 2026 · 13 min · PwshTips

Protecting a PowerShell Watchdog Script from Tampering

In the previous post I built a cellular APN watchdog: a PowerShell script on disk plus a scheduled task running it as SYSTEM every five minutes. It works. Now look at what I actually built, from an attacker’s point of view: a file that, when modified, executes arbitrary code as SYSTEM on a timer. Every monitoring script, remediation script, and fleet “proactive remediation” has this shape. If you would not leave a SYSTEM shell lying around, do not leave a writable SYSTEM script lying around either. ...

September 29, 2026 · 9 min · PwshTips