Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
virtue [ˈvəːtjuː] n (moral correctness) доброде́тель f (advantage) преиму́щество; (merit) досто́инство
by virtue of благодаря́ +dat
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.