There's plenty of research to show if you put even normally honest people in a toxic dishonest environment then they soon will be the same.
Most people think they'd be the person who would buck the trend and speak out or resist, most people would be wrong. It's very easy to self-justify with the 'but everybody is doing it' angle.
The good news though is the opposite works.
If you put people who are inclined to live on the edges of what is right and wrong in an environment where people are honest and hard-working, they are more likely to adopt those attributes.
There is nothing either good or bad, but thinking makes it so.