New version of avast! antivirus kernel features outstanding detection abilities, together with high performance. You can expect 100% detection of In-the-Wild viruses (the ones that are really spreading amongst people) and very good detection of Trojan horses, all that with only a minimum number of false alarms.

The kernel was certified by ICSA; it frequently takes part in the tests of Virus Bulletin magazine, often yielding the VB100 award.

Simple User Interface

Simple User Interface is used to start on-demand scanning, work with the results, change various options etc. Basic resident protection settings can be modified here.

Simple User Interface is the main application of avast! 4 Home Edition. You can start additional avast! modules from here, such as the Virus Chest, Updater or Log Viewer.

The appearance of Simple User Interface is very flexible. It supports so called skins, i.e. changeable appearances, so there are many possibilities the interface can look like. The main package contains three skins, additional ones can be downloaded from our web pages.

Enhanced User Interface (Professional version only)

In addition to the Simple User Interface, the Professional Edition presents the Enhanced User Interface, giving you all the features and possibilities for extensive scanning.

Unlike the Simple User Interface, the scanning is performed by so called "tasks". First, you define a task, including various parameters - areas to scan, what to scan, how to scan, etc. Having the task, you can (possibly repeatedly) run it. Each task generates a list of results; you can work with them later.

Another important feature, closely connected with tasks, is the Scheduler. It gives you the ability to schedule the tasks running, either one-time or periodically.

Of course, it is possible to set all the existing options of scanning (task), not available in the Simple User Interface.

Resident protection

Resident protection, i.e. the real-time protection of the computer, is one of the most important parts of an antivirus program today. avast! features a powerful resident module that is able to detect the virus before it has any chance to infect your computer.

avast! Home Edition contains resident protection of the computer file system and resident module for e-mails.

The file system protection ensures that no virus will be started on the computer. It offers a wide range of settings - e.g. it is possible to specify that files will be scanned during copying, or that the scanning will include files with given set of extensions only.

E-mail protection consists of two independent modules; first, there is a generic scanner working on the SMTP/POP3/IMAP4 protocol level. It is capable of protecting any existing e-mail client that uses these protocols. Second, there is a special plugin for MS Outlook only; it is completely transparent, requiring no special settings.

New feature of version 4 is heuristic analysis of e-mail scanners. It is extremely useful in protecting against new, unknown viruses and worms that are not possible to detect by the usual means. The heuristic module performs a thorough investigation of every e-mail message and watches for suspicious signs that might announce virus presence. When the number of those signs exceeds the user-defined level, the message is considered dangerous and the user is warned.

Script Blocker (Professional Edition only)

The resident protection of the Professional Edition includes an additional module, not contained in the Home Edition - Script Blocker. This module watches all the scripts being executed in the operating system (so called WSH scripts - Windows Scripting Host). It also scans all the scripts run as a part of a web page within your web browser (Internet Explorer, Netscape Navigator and Mozilla).

Automatic updates

Automatic updates are another key point in virus protection. Both the virus database and the program itself can be updated automatically. The updates are incremental, i.e. only the new or missing data are downloaded, thus reducing the transfer heavily. The typical size of a virus database update are tens of KB, the program update usually has hundreds of KB.

If your Internet connection is persistent, the updates are performed completely automatically in fixed time intervals. If you connect to the Internet only occasionally, avast! watches your connection and tries to perform the update when you are online.

PUSH updates (Professional Edition only)

A special feature of the Professional Edition are PUSH updates. It is a dramatic change in the philosophy of updates. Usually, every installed program checks every now and then whether a new version is available. PUSH updates, however, are initialized by our server; they result in your computer quickly responding and performing the necessary update. The system is based on the SMTP protocol, i.e. on usual e-mail messages. The updates itself are controlled by the avast! resident e-mail providers (MS Outlook and Internet Mail).

The whole system if protected by asymmetric ciphers and is resistant to unauthorized misuse.

Virus Chest

The Chest can be thought of as a folder on your disk having special properties that make it a safe, isolated place suitable for storing certain files. You can work with the files in the Chest, even though with some security restrictions.

The main properties of the Virus Chest are complete isolation from the rest of the operating system (no outside process, i.e. no virus either, may access the files inside) and the fact that the files inside the Chest may not be run (i.e. there is no danger in storing viruses there).

System integration

avast! antivirus features outstanding integration into your system. The scanning can be started directly from Windows Explorer, by clicking a folder or a file with your right mouse button and selecting the corresponding choice from the menu.

Another interesting feature is a special screen-saver that performs scanning for viruses during its run-time. avast! antivirus works together with your favorite screen-saver, so you don't have to change to anything you wouldn't like.

Another new option is the boot-time scan (Windows NT/2000/XP/.NET only). It is important in the case that a virus is suspected to be active on your computer. The boot-time scan is performed before the virus may get activated, so the virus cannot influence the scanning in any way.

Command-line scanner (Professional Edition only)

Experienced users may like another Professional Edition feature - command-line scanner. The scanning can be controlled by many arguments and switches; to use as a pipe filter, a special STDIN/STDOUT mode is available.

The module is intended to be used in BATCH programs. Its output is the same as the output from the Enhanced User Interface tasks (including the report files).