Michael Cohen said his former client, President Trump, might be attacking him and his family because he's afraid of being linked to the illegal activities that led to a three-year prison sentence for Cohen.

When asked if Trump is afraid, Cohen said it “seems like it,” and said lashing out is “what he does.”

“I took responsibility for my actions. And instead of him taking responsibility for his actions, what does he do? He attacks my family,” Cohen told George Stephanopoulos in his first public interview since his sentencing. “And after yesterday, again being before the court and taking the responsibility and receiving a sentence of 36 months, the only thing he could do is to tweet about my family?”

In a series of tweets Wednesday, Trump attacked Cohen’s family by saying it was “let off the hook” because Cohen agreed to a plea deal, and argued that he was not guilty of campaign finance law violations.

“Cohen was guilty on many charges unrelated to me, but he plead to two campaign charges which were not criminal and of which he probably was not guilty even on a civil basis,” Trump tweeted. “Those charges were just agreed to by him in order to embarrass the president and get a much reduced prison sentence, which he did-including the fact that his family was temporarily let off the hook.”

When asked if he was afraid of Trump, Cohen said it’s not good to be on the wrong side of the president, and added that he will spend the rest of his life trying to fix the mistakes he made.

“How are you going to do that?” Stephanopoulos asked.

“I don't know,” Cohen said. “One day at a time.”

[Read more: Michael Cohen: Trump 'does not deserve loyalty']