How can I check potential scammer?

[#1]

I have been offered a job with a good pay but the client out of the blue sent me the offer without discussing the job prior. 
Here is the offer - https://www.upwork.com/nx/wm/offer/24854743

Now, how can I verify if this client is legit or a scammer? 

He shared a rar file over email and gave me a password to open the file. I am familiar with this kind of scams. As you extract the file, you pc gets virus and you loose everything. 

Can anyone help?

[#2]

Jobpost already removed.

One thing: you have broken ToS with sharing your email without contract. Want to be banned?

[#3]

Also the offer is still showing. I am a bit confused!

[#4 · Accepted solution]

Thank you for the warning and for your help. 

I thought as the client already sent me the offer, I can accept files from him via email.

But then I got suspicious and came here seeking help. I do not have the mentality to break any rules. 

Also can you point out ways how scammers can be detected? 

Thanks again!

[#5]

For sure:

You asked for outside contact. Eml, telegram, skype.

Scammer ask for test job\interview without contract.

Direct contact with price greater than your default.

Thats all. Other possible when you will broke rules. At your example: scammer will never send virus via Upwork messages.

[#6]

Thank you very much! Appreciate your help.