Is My Internet Being Hijacked? A Sudden Speed Drop from 900 Mbps to 4 Mbps

Have you ever experienced a drastic slowdown in your internet speed and felt powerless to fix it? If so, you’re not alone. Recently, I faced a baffling internet speed issue at my home in the Pacific Northwest, and I need your insights!

The Setup

I’ve been enjoying CenturyLink fiber internet for about nine months, usually benefiting from impressive speeds of around 950 Mbps down and approximately 500 Mbps up. Everything was running smoothly until one day, my download speeds plummeted to an astonishingly slow 4 Mbps! To make things more confounding, speed tests would fluctuate unpredictably—sometimes showing 20 Mbps, other times 100 Mbps, and even dipping to 1.5 Mbps, while my upload speeds remained remarkably high, often reaching 900 Mbps.

The Investigation

In my quest for answers, I reached out to CenturyLink’s customer support. After multiple diagnostic tests, the technician assured me that there were no problems on their end and scheduled a field technician to come investigate. The technician arrived, inspected the newly installed line, replaced the modem and the Optical Network Terminal (ONT), and even ran new Cat6 cables. Despite conducting all tests through a wired connection (and noting that Wi-Fi performance was even worse), the situation remained unchanged.

Throughout the visit, the tech continuously inquired, “Are you sure you’re not using a VPN?” This puzzled me, as my understanding of VPNs is minimal. The technician left scratching his head, and I returned to tech support, only to hear the same lines: “Everything looks fine,” and once again, the mysterious VPN question surfaced.

Additional Concerns

To add to the mystery, I’ve encountered unexpected CAPTCHA prompts when searching on Chrome, with messages indicating suspicious activity on my network. This raises more questions: Could someone be accessing my internet without my consent? Is there a possibility that someone has inadvertently configured a VPN on my connection?

Seeking Help

I’m reaching out to the community for help, as I feel a bit out of my depth. Are there specific steps I can take to determine if someone is using my internet? Is there a way to check for any unauthorized VPN setups? I could really use some guidance to resolve this perplexing issue.

Update: I’m typing this at 4 AM and haven’t found a solution yet, but I sincerely appreciate all the feedback I