I came home yesterday to find my daughter on the phone with a "tech support agent." She wanted me to talk to them, explained that she had gotten a popup that wouldn't go away and called the number it told her to. I told her to hang up the phone and grilled her for details. She had downloaded GoToAssist and let the "tech support person" have control of her computer. After shutting off the internet to her laptop from the router and giving her a nice long lecture, I proceeded to run some scans.
I scanned her laptop which runs Windows 10 with Windows Defender, Malwarebytes Adware Cleaner, Malwarebytes and Hitman Pro. They all said that no threats were found, but when I went back to Windows Defender and looked at the scan history, I found that Trojan:Win32/Ditertag.B was shown under the full history in both Quarantined Threats and Allowed Threats.
At some point, GoToAssist disappeared from her desktop, and I subsequently uninstalled something with a similar name (GoTo?????) that I forgot to write down. I'm not sure where to go from here. I restarted in Safe Mode and the Ditertag.B is no longer showing up under Quarantined Threats or Allowed Threats, but I'm sure it didn't just disappear on its own.