Someone correct me if I'm not remembering things correctly, but I think without getting too bogged down on the details....
From RR Path: ALT is mostly found in the cytosol, while AST is mostly found in the mitochondria.
Alcohol is toxic to mitochondria. Viruses, as you know, do their thing leading to cell death and the cellular contents spill out.
Also, I remember from GI block in school that Vitamin B6 is essential in the synthesis of aminotransferases with some preference to ALT. Alcohol decreases B6, so ALT suffers (contributing to AST >> ALT).