I got my Android 2.3.7 ZTE phone used on eBay, and it appeared to be completely reset. However, sometimes hundreds of contacts with names like "brwlvweaace" show up. They all have randomized emails, like "firstname.lastname@example.org". It almost seems like a list of generated emails for spamming. I can see them when choosing a contact to send a text to, and if I add the "All Contacts" folder to the home screen. The SIM card is new, and shows 0/250 contacts. The SD Card was new as well, and formatted on top of that. I don't have these contacts in any synced account. And I can't delete them, because they never show up in the main Contacts app.
How do I get rid of them? I only have about 15 real contacts, so it's a pain to send a text message to one of them when the list has hundreds of fake names.
Here's a picture: