Samsung Galaxy S3 Stuck at Samsung Logo, possible virus? My Mom has a Samsung Galaxy S3 from 2 years ago, it now gets stuck at "Samsung Galaxy SIII GT-I9300" screen and can't boot properly. It can't enter Recovery Mode either but can enter Odin Mode.

Also tried to remove the battery, plug the charger cable and insert the battery but it gets stuck at "Loading Battery", showing a frozen gray battery in the center.

When tried to get it repaired, the repair specialist said it was a virus and it would be very expensive to get it repaired (warranty doesn't cover it).

Searching online, I found someone with the same problem, and answers to that post instructed to enter Odin Mode, connect the Phone via USB to a machine with Samsung Kies installed and let it download a new Firmware.

I should do it? I'm feeling a little reluctant to do it since the repair specialist mentioned a virus (don't know if a phone-oriented virus can affect a PC)

Thanks for reading,

LeoAM.
Odin mode is run in a very very early stage of phone boot - that's why you don't see the phone logo when entering Odin mode. The virus (if it really is the problem) will not have a chance to execute its malicious code because the bootloader isn't even running in Odin mode. 

So yes, you can safely Kies your way back to working condition, but sometimes you should use the specially created Odin program (Google it, I can't give links right now as I'm on a slow connection) to flash the firmware by yourself if Kies doesn't feel like working.

Just note that either way, you'll have to download 1+ GB of firmware.