HT4993 Why did I see a pop up window on my iPhone 4S that said "Apple Back Door"?

Question

I went to Berlin, Germany and took my iPhone 4S. Before I left, I asked my carrier (Sprint) and the ignorant technician told me that if I wanted to use my phone for texting and calling locally in Germany, I just needed to go to any phone store and buy a sim card. Well, I did, and the sales technician in Germany was not well versed with iPhones, so he tried twice to put in a Vodophone sim card, but it wouldn't work, and a 4 digit blank pin number page appeared, which at that time, I realized my iPhone was LOCKED. Sprint failed to tell me that. In any event, I used the phone over wifi to acess FB and other apps, which worked okay. Sprint also failed to tell me that I could have used iMessage over wifi to text my friends in Germany who also had the 4S, shame on Sprint, they shouldn't put an 18 year old at the desk who doesn't know blank! This time, I was really upset with Sprint.
But my question now, is when I opened a few apps, and it only happened twice, once in Germany at the Airport when I was about to leave, and once when I arrived back in the States, once I got off he plane and searched for a signal (I kept the iPhone in "airplane" mode all the time I was in Germany), a window quickly appeared and disappeared, but all I could see was on the top header of the white window, it said, "Apple Backdoor", and quickly turned as if was apage, and disappeared, and I still continued on. It didn't block anything I was trying to do on the phone, but I went to both Sprint and the Apple retail stores, and no one seems to have an answer, or even have said they never heard or seen such a window or app named "Apple Backdoor". Does anyone have any information on this? It is kind of making me suspicious of the technician in Germany, was he trying to access my iPhone's personal data (he took a long time)? Or was I being tracked by anyone, or perhaps government tracking because I was going overseas? I even tried to Google it, and all I come up with is something related to the FileApp Vault, which is about a Mac computer, not about an iPhone. There was an article written back in 2010, about the Indian Government exposing a flaw in the iPhones, accessing them through exactly what was worded "Apple Backdoor". Please, anyone, do you have any information on this, and do I need to take any precautions, or should I reinstall the new I OS 6 (the Apple technician at the retail store suggested it if I felt very uncomfortable).
"Apple Backdoor" - what is it, what does it mean - only for iPhones, not macs or iPads?

Answer 1

It's not a virus. It's a JavaScript scam that only affects your web browser, and only temporarily.
Some of those scam pages can be dismissed very easily. Press command-W to close the tab or window. A huge box will pop up. Press the return key and both the box and the page will close. If that doesn't happen, continue.
From the Safari menu bar, select
Safari ▹ Preferences... ▹ Security
and uncheck the box marked Enable JavaScript. Leave the preferences dialog open.
Close the malicious window or tab.
Re-enable JavaScript and close the preferences dialog.
If the Preferences menu item is grayed out, quit Safari. Force quit if necessary. Relaunch it by holding down the shift key and clicking its icon in the Dock. From the menu bar, select
Safari ▹ Preferences... ▹ Privacy ▹ Remove All Website Data
to get rid of any cookies or other data left by the server. Open your Downloads folder and delete anything you don't recognize.