Stop avast! from attacking my own programs
You have to disable Avast DeepScreen:
Open Avast user interface>Settings>Antivirus uncheck, Enable DeepScreen.
It is now a much smaller option on the same page, (6th one down)
The option is harder to find (in my opinion) for the different version I have (version in the image).
In Avast Premier 2017, disabling Hardened Mode does nothing! Instead you have to disable CyberCapture as shown below:
According to a user manual that I was able to find for version 4.8(see page 40), You need to do as the comments suggest and add your obj directory or bin directory to the exclusions list.
According to a post I found in the Avast forums from 2011 you can also add exclusions for single files by:
...manually edit[ing] the line where the path for the exception is. So, using the "browse" button, select first the folder, and then edit the resulting path and "add" to exclusions. You can also use "*" and "?".
As others have mentioned, the culprit is DeepScreen. It's especially bad if you have Avast set to Silent/gaming mode because then you can get unexpected/bizarre behavior and have no idea why. (I spent an entire day debugging the installer for a program I'm developing because it suddenly started running twice every single time I launched it--DeepScreen is very forgetful--and only succeeding on the the second run.)
Going under Settings, Update, Details, you can turn off popups for the majority of them--the annoying update-related popups, which should make it easier to work undisturbed, play video games, etc. But DeepScreen popups still pop up!
CANNOT DISABLE DEEPSCREEN: I've tried disabling DeepScreen entirely (under Settings, Antivirus), since it's so disruptive, but this checkbox appears to have no effect.
Unfortunately, the only way I currently have of disabling DeepScreen (in Avast 2014.9.0.2021) is to disable all shields! And I'm not even sure that this is working, since I sometimes get DeepScreen popups even with all shields disabled. Avast can't be prevented from starting with Windows during boot, so maybe uninstalling Avast is the only solution.