How to detect who is downloading apk files in background? At some point in time my Android phone start downloading some .apk files in background. I assume this is doing some of the free apps what I've installed on my new phone from Google Play (I've installed 30-40 new apps recently). This is very annoying, but I can't get rid of it. I've tried to scan for viruses by antivirus app, but it found nothing.

How can I detect exactly which app is periodically downloading apk files in background?

Update:
In notification bar I can see only usual notification about that .apk file was downloaded successfully. If I click that notification, it opens usual "Downloads" app with list of downloaded files. Here I can see files that I've downloaded by myself and files that was downloaded by some app in background. So, files are downloaded by native browser, I think.

My phone: Sony xPeria Sola, Android OS 2.3.7
Probably the quickest fix is going to be when it downloads an .apk, go to the notification, long press it, and when "App Info" pops up, click it. It will open in the application manager the app that downloaded it. (It may not be available on your phone, but it works on my S3.)

Your application manager is another wealth of information. There are way too many specifics to get into much detail about, but for example an app that is supposed to be offline, look at it's data usage. If it has used several MB of data, there's your culprit.

You could also narrow down the suspects by looking at the permissions. If it doesn't require network access, it can't download anything. (Although if this doesn't work, I'm not sure how trustworthy the permissions tags really are if we're dealing with a Trojan).