With accent marks:
Дурно́й приме́р зарази́телен.
A bad example is contagious.
Bad habits and wrong views of one person very often “stick” to other people.
The proverb is used to talk about a person who, without any thinking and hesitation, adopts bad habits of others.
Other Russian proverbs
Оne sees the mote in another's eye and ignores the log in his own.
You can't spoil the porridge with butter.
The eyes are scared, but the hands are doing.
Crowded, but not aggrieved.
Put your trust in God, but don't make mistakes yourself
If you are chasing two hares at once, you won’t catch a single one.
Hurry to much and you will make people laugh.
The morning is wiser than the evening.