This came up in a rules discussion today. When the Corp player uses the Purge Virus Counters action are all virus counters in play discarded? The definition in the rule book for the action says to "remove all virus counters hosted on cards" (boldfaced in the rulebook).
So, that lead us to the question of are all virus counters considered to be hosted on the cards they are on even if the card dosen't actually use the word "hosted?" There are some cards that specifically use the term and some that don't.
Example 1. Imp
Place 2 virus counters on Imp when it is installed. Once per turn, you may remove 1 hosted virus counter to trash a card you access at no cost (even if it cannot normally be trashed).
Example 2. Medium
Whenever you make a successful run on R&D, place 1 virus counter on Medium.
Each virus counter after the first on Medium allows you to access 1 additional card from R&D whenever you access cards from R&D.
Am I correct that both Imp and Medium lose all virus counters if the Corp purges?