We see a lot of such viruses at the moment.
Clamav is desperately behind all other AV's at the moment...
Example: https://www.virustotal.com/de/file/bf84db71be81fa27d0d796d000347d47ef0dcd814...
Known since at least one week. Clamav still does not recognize it.
I have submitted the sample to the clamav team directly now.
Mit freundlichen GrĂ¼ssen
Benoit Panizzon