Both ‘unaware’ and ‘unawares’ are correct.
Unaware (adjective)
Not having the knowledge or realisation of something.
Examples:
- Was he unaware of the threat?
- They were unaware that she was their lecturer.
Unawares (adverb)
Unexpectedly without any warning or sign.
Examples:
- He was caught unawares by the question.
- My entry took the looters unawares.
