Officially you cannot add “apps” to a version v2.x My Cloud. Unofficially one might be able to add an AV scanner to a My Cloud by hacking the My Cloud firmware using SSH to install the same AV scanner that is used by the more expensive, multi bay, My Cloud units. Or one could try to install ClamAV somehow (https://www.clamav.net/). The problem comes with trying to install an AV scanner on the OLDER gen 1 v4.x My Cloud’s due to the different page size used on those versions.
It should be noted however that the processor/RAM used on the single bay My Cloud is low powered and using a virus scanner could potentially slow the My Cloud to a crawl. See the following discussion where the WD AV software for a multi bay My Cloud slowed their unit to a crawl.
https://community.wd.com/t/anti-virus-essentials-app-making-drive-too-slow/135688
One way to scan the My Cloud is to “map” the My Cloud to the local computer then use your computer’s anti virus software to scan the drive, would take a while but it is possible.
http://support.wdc.com/KnowledgeBase/answer.aspx?ID=2676
Others have requested an AV scanner for the single bay My Cloud units in the Cloud Ideas subforum:
https://community.wd.com/t/please-add-an-anti-virus-solution-maybe-based-on-clamav-to-my-cloud/97179
https://community.wd.com/t/allow-users-to-install-anti-virus-software-on-mycloud/97016
