Hi,
you need to have an updated antivirus before attempting to open the file.
if this part it fine, you may scan the folder and see if the antivirus detects the trojan.
if nit, then you will have to extract the file, do ing so will allow its detection by the antivirus ans it will be removed.
but still, the virus will remain in the rar file.
you may zip the extracted folder then.