As of 19 March - this IDP.Alexa.51 has appeared on my computer as well.
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Now I've got a file in virus chest, which I cannot delete - any help, please.
There is no rush to delete anything in the chest, a protected area, more so if this a file that has been on your system for a long time.
If you consider the detection to be a false positive:
1. open the virus chest and submit it to the virus labs.
2. if you accept the risk, you can Restore and add it to exclusions (in one action).
There will still be a copy in the chest, just leave it there for a while it won't hurt. By the time this delete from the virus chest is resolved scan it within the chest and if it is no longer detected, then delete it.