Slow computer performance (taking a long time to start up or open programs).
The answer is YES, they can hide in many other places, not only into your HDD, but also into other storage devices you have connected to your PC. In Summary the virus can be resided at bios or at any source but it requires some point of execution which lacks at hardware.
Does formatting a drive remove Windows?.
Is it better to quarantine or delete a virus?.
How do I wipe my computer of all viruses?.
What is the most dangerous computer virus?.
Does a factory reset get rid of viruses?.
How do I know if my hard drive has a virus?.
How do I check if my hard drive has a virus?.
Will changing hard drive remove a virus?.
Can you destroy a computer with a virus?.
How do I remove a virus from my hard drive?.
Is it better to replace a hard drive than to try to remove malware?.