Possible ad-malware attempt

For the last several days my Android tablet was opening windows at random.  At first I thought it was me, but, yesterday the following happened and the tablet was sitting on the table untouched:

• Multiple search windows open;
• Over 12 tabs opened in the browser going to a number of sites with the same prefix.  I won't name it as I don't want them to get the ad revenue;
• My BANKING app was opened up.  I don't have auto-sign-in there so no damage done.  I checked the bank account from my Linux machine and no activity to my account (yay!);
• Multiple apps opened up.  Again these had ads so I suspect they were trying to maximize their ad revenues.  Either that or they wanted someone to pay a lot of ad money for spam clicks;

I know what the last app I installed so I suspected that app as they are ad supported.  After I removed the app and let the machine sit for 24 hours I had no more random windows opened so I may have guessed correctly.

I also run AVAST on the machine and I scanned everything and it was clean.  I know if it is very new the scanner may not detect it, but, I wanted to make as sure as possible I wasn't infected with a known virus.

I also sent Google a feedback that the app may have ad-malware and see if there is anything that they could see and do.  May not be much, but, at least I wanted to make them aware of the issue.