Avast is reporting that the quero toolbar exe has a virus in it.
Virus has been detected!
File Name: Quero Toolbar 4 Build 4.0.1.1 Setup.exe
FileID: 4
Virus Description: Win32:Trojan-gen {Other}
Is the a False Positives?
To know if a file is a false positive, please submit it to VirusTotal and let us know the result. If it is indeed a false positive, send it in a password protected zip to virus@avast.com
Please, mention in the body of the message why you think it is a false positive and the password used. Thanks.
Other possibility is JOTTI. VirusTotal and Jotti both have file size limits 10 and 15MB each.
As a workaround, you can add these files to the Standard Shield provider (on-access scanning) exclusion list.
Left click the ‘a’ blue icon, click on the provider icon at left and then Customize. Go to Advanced tab and click on Add button…
You can use wildcards like * and ?. But be carefull, you should ‘exclude’ that many files that let your system in danger.
After that, please, periodically check it - scan it into Chest, right clicking the file - there should still be a copy in the chest even though you restored it to the original location. When it is no longer detected as being infected then you can also remove it from the Exclusion list.
Why that was fast!
The latest Avast update fixed it. 
They’re usually very very fast on fixing false positive detections.