there are a lot of good Android anti-virus apps out there. av-test(dot)org tests a bunch of vendors every quarter or so. check them out for more detailed reviews.
Kaspersky
ESET
Sophos
Avast
Armor for Android
all consistently test well. Disclaimed i work for Armor for Android, so of course i believe they are among the best. However, Armor for Android does not offer a free version so if you need free try one of the others.
in response to loner.
"This is troubling.
A report saying 96% of apps have vulnerabilities."
that report is pretty liberal with what it considers a vulnerability. There is a lot of bad stuff out there, but saying 96% of all apps have "vulnerabilities" is a bit irresponsible of that report.