Weird issue maybe someone else has seen?

It can't be a virus:

There are currently no viruses for Mac OS X in public circulation, only a handful of trojans and other malware, which have to be installed manually via entering the administrator password.
The only anti-virus you need to protect your Mac is education and common sense.
Also know, that the term "virus" is often used to refer to other kinds of malware, but there are differences, which you can find out by reading the following:
Mac Virus/Malware Info by GGJstudios​

Anyway, does your friend have the ability to get a new battery or bring it to Apple?

 

Reset the SMC. This should answer most, if not all, of your battery questions:

Apple Notebook Battery FAQ​

It's not malware. Macs are not immune to malware, but no true viruses exist in the wild that can run on Mac OS X, and there never have been any since it was released 10 years ago. The only malware in the wild that can affect Mac OS X is a handful of trojans, which can be easily avoided with some basic education, common sense and care in what software you install. Also, Mac OS X Snow Leopard and Lion have anti-malware protection built in, further reducing the need for 3rd party antivirus apps.

Mac Virus/Malware Info​

 

The email isn't responsible for this behavior. Did your friend try resetting the SMC/PRAM and calibrating the battery? Does it do this when the battery is not in the machine?

 

Just to clarify, PRAM/NVRAM has nothing to do with battery/power/charging issues. Resetting it will not help. Only resetting the SMC addresses such issues.

 

There are three primary components to the charging system: the MagSafe adapter, the battery and the logic board. Check the link in the CHARGING section of the Battery FAQ for troubleshooting MagSafe adapters. Use iStat Pro to get accurate readings of your battery condition. Calibrate the battery using the instructions in the CALIBRATION section of the FAQ. You've already reset the SMC. If none of that helps, that means the problem is likely with your logic board. It could be something simple like a loose connector, or something more serious, requiring logic board replacement.