Good for you! I fell into that trap, but not through Upwork. The one accepting the proposal told me to contact his partner via email. The partner welcomed me, gave me a set of criteria, and said "we'll work through Skype." I didn't catch on until I'd written a few articles. Here are some of the things that stood out:
- they say they pay per word, and the amount is usually between 5-10 cents
- they want you to go to Skype
- they'll use two people to set you up
- they'll push for 3 - 5 articles per day, or the equivalent of 3000 words
- they will provide a schedule for pay day, but when the time comes, they'll have an excuse - the one I heard was that they were trying to "standardize the times" that they were paying everybody
- their logo on Skype was a canned image (I'd seen it online before)
I hope this helps anyone who encounters these type of scammers.