Carrier Notes on iPhone 5 contains login info??

Hello! I apologize if this is a duplicate but I searched and no one has this issue.

I retail iPhones through Canadian carriers and had a recent customer with a strange dilemma. Their notes section contained a note not written by this customer containing all login names and passwords.

The iPhone is not linked with any other devices via iCloud or email. Nothing is linked to this iPhone at all! (Different emails, different iCloud accounts)

I haven't heard tell of a similar issue at any point in time, and Google didn't turn up any relevant info.

Anyone familiar with this and what the root cause may be? Theories accepted too!

I would be inclined to believe, but alas, the customer is always right...

(Please read with extreme sarcasm)

The customer fully believes her iPhone 5 was hacked and/or implanted with some kind of virus.

I think that the above post is correct, that there was something done that copied secure information.

I didn't sell this particular phone... and I have relayed allllll the information I could find on the likelyhood of a virus on an iPhone, but you know how people are!

There is a ticket logged with a technician right now, with whom this person works. We'll see if they can convince this novice iPhone user that there's nothing wrong with their phone, since clearly I'm not doing a very good job of it.