I am new to crypto so it's a hard lesson learned.. Probably no way to get it back now obviously but Watch out guys..Not sure how it was done as I logged into Stellar viewer and everything was gone. Not much but enough to me.
GBIF7KAUIKZ7YDGLHVLEY72QVUNTBFLHTBF6PAIT7MH7OHJFQWPXAIBOAsset Balance LimitXLM 141490.6805600
looks like they go through binance mostly. You never mentioned the amount so it would be hard to pinpoint. Contact Stellar about it.
What website did you go to? If it wasn't www.stellar.org/account-viewer/ then it wasn't the official account viewer.
Be aware of scams and phishing attacks! Stellar.org doesn't give away free lumens anymore except through physical meetups.