"had been aware" is correct and can be used in spoken and written English.
Example sentence: "John had been aware of the danger from the beginning, but he didn't want to admit it."
We had been aware of the school's existence for a long time, but seldom discussed it.
I asked McCain if he had been aware of Kerry's touch.
Neither the paper's reporters nor its sources had been aware of the series, the executive said.
Later, Mr. Adoboli said others at UBS had been aware of his actions.
Mr. Shulman indicated Tuesday that he had been aware of those findings.
She said NBC had been aware of the limits of G4's programming niche.
Later, he claimed that some of his colleagues had been aware of his actions, prosecutors said.
He said American officials had been aware of the deaths and had immediately started an investigation.
But he said both men had been aware that a text was being drafted.
Neither his company nor the United States government had been aware of this problem.
Even so, some passengers interviewed Friday said they had been aware the plane was off course.
