RED flag! Don't ever fall for such, it's a scam.
#aThread
First things first, if you received a job offer from an employer, it should contain;
1. Employers full address and details.
2. Complete job description with details of what your responsibilities would be.
3. Salary/hourly rate
5. Coverages (medical insurance and the likes, what is covered and what is not).
6. Annual vacation/compulsory leave
7. Signed by HR or with company stamp.
8. It must be addressed to you personally not a generic write up.
Here is a link explaining how the temporary foreign worker hiring process works
bit.ly/2NlYUh7
Here is a link tgam.ca/3dvAkoUp
to an investigation made by the globe and mail about a year ago, and it exposes..
So, it's a real problem and something you should be wary of...
Canada is largely a DIY country, and you can apply for all these opportunities without any help from any immigration agent/agency.
Visit canada.ca/en.html to start.