One of Capitalism's characteristics I really admire is that Capitalism regards highly of the "contract" based on an objective and visible value such as monetary exchange, physical reward&punishment, and giving a certain status. So, in capitalist system, corruption is not taken for granted to be tolerated without any negative sanction. At least, these corrupted individuals know handling corruption is risky, costly, and evil even though it is necessary for them.
By contrast, under socialism, the means of contracts can be easily biased. Socialism always regards highly of "Society" and "Public interest" which we cannot see or touch. Also it is difficult to clearly define what is society and who are public. So, whenever socialists make a contract, they always mention "For society" and "For public interest" as though all what they do are good for the others i.e. They insist on altruism. Although socialists claim their insisting abstract norms such as society and public interest are the objective value. But, the definition of these abstract norms are highly "subjective" because it is not something visibly existing or affecting us. Therefore, under Socialism, there is a danger that people do not realise the corruption is a corruption. Those who take the action (E.g. Corruption) argue that their certain action (E.g. Corruption) is put into practice for society and based on the public interest.