Viruses and malware are generally intended to perform functions that require your device to be active. It is not in its best interest to damage your phone.
Although it is unlikely that the phone hardware can be permanently damaged by a virus or by other malware, in some cases it may be damaged as an unintended side effect.
Phone Battery
Malware and viruses run in the background of a device. This often causes the battery to drain faster than usual and can cause the phone to heat up. By draining the battery faster, it will require the battery to be charged more often, which can shorten the life of a battery. In this way Viruses and other malware can unintentionally damage the battery over time, if it is active on the device for a relatively long time.
Although malware does not intentionally target the phone battery, there are Scareware doing the rounds that warns the user that there was a battery virus found on the devise and then prompts the user to follow a link to resolve the problem. The message is fake, but it attempts to scare the user into clicking on the link. This link will then take the user to malicious website, which will then attempt to download malware onto the device.
Do not ever click on links on warning messages like these. Instead, exit the message and check your device by using legitimate Anti Malware Software like Norton, or McAfee malware protection.
Overheating
Because malware and viruses run in the background of a device, it can also cause the device to run hotter than normal. As with the battery draining faster, a phone that runs hotter than usual could also be a tell-tale sign that malware is present.
When a smartphone overheats, it could potentially cause permanent damage to the phone. Particularly to the SoC system chip. It is unlikely that this will happen however, as most smartphones has built in protection against overheating.
When a phone overheats, the built-in protection will typically slow the operating speed of the chip to reduce temperatures. If the overheating continues, a warning message will pop up and then shut the device down, to prevent permanent damage.
The bigger risk
As explained above, the risk of physical damage to a phone by a virus or other malware is relatively low. The bigger risk lies in the data on the device that could potentially be compromised.
Cyber attacks are generally aimed at financial gain. This can be accomplished by compromising your personal data on the device, such as banking information and login details.
By comparison, the financial loss that could be incurred when this information is compromised could be far worse than a damaged phone.