The phrase "corrupting influence" refers to something or someone that has a harmful and negative impact on others, often leading them to engage in unethical or immoral behavior. Full definition
A bill passed by the General Assembly last year further weakened the Citizens Election Program's defenses against the potentially corrupting influence of outside money. (courant.com)
Hmm... Leisure Suit Larry appears to have had some sort of corrupting influence on you. (games.slashdot.org)
And Lancaster asked no questions about corrupting influence. (gelbspanfiles.com)