Avira's AntiVir Premium Edition lacks an advanced malware detection feature used by top programs, and it could use a smoother interface. The program earned a seventh-place ranking in our current stand-alone antivirus roundup.

AntiVir proved capable at detecting known malware, detecting 99.3 percent of AV-Test.org's collection of more than half a million samples of Trojan horses, worms, spyware, and other kinds of malware. In past tests, that kind of showing would have earned a top rank in the category.

But in this roundup, the apps we tested proved so adept at detecting older, known malware that Avira's performance was only good enough for seventh place for traditional malware detection. AntiVir's relative performance was stronger in important heuristic tests, which use 2-week-old databases and newer malware to simulate how well antivirus apps can detect new malware that doesn't yet have a signature. Its 69.2 percent block rate earned it a number two spot, second only to G-Data Antivirus.

AntiVir can scan both Web and e-mail traffic (though not IM traffic, or for browser-tracking cookies) to catch potential attacks before they make it to your hard drive, but the program doesn't yet have the ability to catch malware based solely on what it does (known as behavioral detection, or behavioral analysis). This last line of defense is important for catching brand-new malware that can evade a signature-based defense, and while Avira says the feature is in testing for its standalone app, you'll have to do without it for now.

While Avira didn't earn a top spot for malware detections tests, when it came to scan speed the program played second-fiddle to none. Its 14.8MB-per-second throughput rate for automatic scans (these kick off when files are altered, for example) was matched only by Avast in speed tests. The program was similarly strong when it came to dealing with rootkits, stealth malware used to hide other malware on a PC--but so were many of the apps we tested. It detected all the rootkits and removed all but one--not bad, but four of the programs we tested cleaned up all of the rootkit infections.

In disinfection tests AntiVir proved capable at detecting and disabling existing infections, and it removed all the active malware files for all ten test infections. However, it left behind less-important files or failed to reverse system changes in all but one of the infections.

Double-clicking a system tray icon to open the app provides quick access to a straightforward status display, with links for performing an update or scan. But if you want to dig into any of the program's settings, you'll almost certainly have to go beyond the bare-bones standard settings display and opt for the expert mode. And when the app detects a threat, you'll wish you were an expert when faced with as many as seven different choices in the warning pop-up.

When Avira's AntiVir adds behavioral detection, and ideally an updated user interface and warning pop-ups, it may become a better option. Until then, you're likely better off with other products.