There's an index right there in the tweet. Searching 'jobs' or 'hiv' gets you this file.
So, essentially, a purported medical document indicating that Steve Jobs tested postive for HIV in 2004. That has long been a rumour, which was always denied. If this is genuine, then that rumour was acually true after all.
ETA: the McCain thing is apparently about him not declaring certain campaign donations. I'm not up to speed on that.