Office corrupted files

What if a file created on MS-Office is corrupted due to some virus? how could we recover the useful data out of it?

This topic requires the benefit of Malware Removal Specialist assistance, which is not available in Software and Hardware Forums.
If you believe your machine or data is infected, please post your Topic into the Virus, Spyware, Malware Removal Forum.

Most third-party antivirus products (Avast!, AVG, Avira, McAfee, Symantec, Kaspersky, etc) detect and prevent, repair or remove malware that infect files, in addition to malware that infects the computer system. Generally, malware that infect MS Office files are referred to as Macro Viruses. Opening files infected with Macro viruses can infect other MS Office files and also infect the machine system in general

If you have downloaded a file infected with a Macro Virus, or others of your files have become infected with a Macro Virus, the first order of business is to kill the infection.
For killing/removing infections, we refer you to Virus, Spyware Malware Removal Forum.

Once the Macro Virus has been killed/quaranteened/removed, the user may be able to move on by using a back up copy of the original document before it was infected.
If a back up copy is not available, there are specific third-party tools that can be used in some circumstances to reconstruct the remnants of a cleaned file that was previously infected.

Your Topic highlights the importance of regular use of Best Practices for safe and secure computer use:

Keep your operating system updated
Keep your antiMalware utilities updated and operational
Do not download files from unknown or suspicious sources.
Scan all files that you allow onto your machine, including files that you may have received from "friendly" sources.

Thanks for the info