This KB article discusses if Exinda can detect whether or not cached data is infected.
Exinda cache works for any traffic that is on port 80 (HTTP). As long as the data is cacheable, it will be stored in the Edge-cache memory of Exinda.
When Exinda serves content from the cache, it first checks with the web server to see if the content has changed or not.
If the content has not changed, then the data is provided from the cache.
If the content has changed, then a fresh copy of the data is downloaded from the server and stored in the cache.
Any future requests for the same data go through the same process of checking for updated data from the server.
Exinda has no way of finding out if the cached data is infected. Unfortunately, if the copy of the data on the server is also infected, Exinda would keep on serving the infected data to all the clients requesting for it.
As soon as the copy on the Web Server is cleaned, Exinda would be able to detect a change in the data and grab a fresh clean copy of the data from the web server.