“AVASoft Professional Antivirus Firewall Alert has blocked a program from accessing the internet” is a fake security warning caused to be displayed by a rogue antivirus called AVASoft Professional Antivirus. It as many other rogue applications of the same family uses the same “Firewall Alert” to make victims think their computer is badly damaged. One of the typical warnings is about infected web browsers that should be closed to avoid possible data loss. Below is an example image of an alert informing about Internet Explorer blocked by a worm Svchost.Stealth.Keyloger. Please note, such a worm does not exist. Moreover, it would not steal sensitive information.

Complete quotation from AVASoft Professional Antivirus Firewall Alert has blocked a program from accessing the internet:

Avasoft Prefessional Antivirus Firewall has blocked a program from accessing the internet
Internet Explorer Internet Browser is infected with worm
SVCHOST.Stealth.Keyloger. This worm is trying to send your credit card details using Internet Explorer Internet Browser to connect to remote host.
Name: Internet Explorer Internet Browser
Location: C:\Documents and Settings\Michael\Desktop\iexplore.exe
Company: Microsoft Corporation. All Rights Reserved.
Version: File Version: 5.1.2600.2180 Product Version: 5.1.2600.2180
Activate AVASoft Professional Antivirus
To ensure continuous protection of your PC, you should activate AVASoft Professional Antivirus on this computer. o you want to activate AVasoft.

Screenshot:

Removal guide:

In order to stop getting alerts similar to “AVASoft Professional Antivirus Firewall Alert has blocked a program from accessing the internet” you should remove the infection causing them to be displayed. We recommend using special AVASoft Professional Antivirus removal tools and follow instructions available. Please note, having this fake antivirus on your computer leaves it unprotected because the rogue blocks existing system security programs.