Jeffrey Lee Parson, 18, made the statements during his first media interview since his arrest last Friday, with US television network NBC's Today show.
Parson revealed he had been questioned by authorities at least four times and said he had been co-operating with the investigation before being charged.
"When I was first approached by authorities, I never thought I was a suspect in a crime," he said.
Of being charged, he said: "I was very surprised. To me it came completely out of the blue that I was going to be arrested and charged with this offence."
Parson twice said he does not have a lawyer and he also admitted to not fully understanding the charges against him, having a copy of the complaint or having the complaint properly explained to him.
The W32.Blaster-B worm is a variant of the W32.Blaster-A worm that infected millions of PCs last month. Blaster-B was released three days after the original worm, according to antivirus company Sophos, and infected far fewer machines than the original.
Parson declined to explain what part, if any, he played in the writing or release of the worm, citing his need to consult a lawyer before going into details. He did say that he believes the government is trying to make an example of him and that he is "not the one they need to get”.
He also said some characterisations of him in the media have been false. He said he is not a loner, not a misfit, not embarrassed about his weight, does not smoke, drink or do drugs and is not reckless.
Martyn Williams writes for IDG News Service