it could be a counterfeit from ecuador. this morning i was at the bank depositing $50 in loose dollars, and the teller pulled out a magnet and held it over the coins; i asked why and she said there have been a lot of counterfeits coming from other countries that use the US dollar and most of them are magnetic
I've pulled Sac's over the last couple of weeks that are just like yours. Pretty sure they were plated.
IT'S FUNNY; last night trying to do Mat. match. between Canadian coinage and American Coinage, I found 1 "very, very, very magnetic cent" from 2003. And two Canadian cent with "No magnetic reaction". I though that the 1 with magnetic reaction IS WRONG. But... Noooop. Those cents were made from steel. As soon I get home today I"ll check the others Canadian Cents.