Editor's Note: Since this review was posted, we've taken another look at Nod32 Antivirus 4 to take into account newer testing methodologies. See the review...

ESET NOD32 has some nice, techie-focused extras and it effectively ferrets out rootkits, but it can't keep up with other antivirus apps when it comes to the essential task of blocking malware. It came in ninth place out of 11 in our current ranking of stand-alone antivirus software.

NOD32 lagged behind every other program we tested when it came to detecting known malware with signatures. Against AVTest.org's huge store of known Trojans, spyware, and other malware, its block rate of 94.8 percent was decent, but strong performance from the majority of the apps we tested has raised the bar.

The Slovakian-based program also fared poorly in adware detection tests. Only Trend Micro Antivirus + Antispyware did worse than Nod32's 88.7 percent detection rate in the category of annoying, but generally not harmful, software.

NOD32 performed better in heuristic tests designed to measure how well security programs can detect newer malware threats. With two-week old databases, ESET's program detected 63.6 percent of newer malware, earning a middle-of-the-road sixth place. But when it came to behavioral detection tests, which measure how well a security app can identify bad stuff based solely on how it acts on a PC, NOD32 put up some warnings but ultimately didn't block any of the brand-new test samples.

The malware hunter was able to identify and block all ten rootkits, which are a type of malware used to hide other threats on a PC. But three other apps--Norton Antivirus, McAfee Antivirus Plus and Kaspersky Anti-Virus--were able to match that performance. For other types of malware infections, NOD32 failed to disable one out of 10 test infections. Again, not terrible, but most of the apps neutered all the test infections.

NOD32 does include some nice extras, such as a new ability to scan HTTPS traffic for threats before they reach your hard drive, and a SysInspector tool that evaluates running programs, Registry entries, files, and other elements of your system for potential risk. SysInspector is meant for techies, but it can provide a wealth of information about what's going on in the depths of your PC (ESET also offers the tool as a free download).

The program's user interface is generally smooth, but it has some definite annoyances. NOD32 splits settings and tasks between a standard mode and advanced mode, and hides some important elements like the quarantine function and scan scheduler behind the advanced mode. Also, if the program finds any threats during a scan you schedule or run yourself, it won't tell you up front what it found. To see anything more than the number of discovered items, like the file's name and location, you'll need to dig into the quarantine or scan log.

Finally, unlike most stand-alone security programs, ESET says its application will conflict with firewall software available from Webroot and ZoneAlarm, unless you turn off HTTP filtering.

NOD32 didn't fall down on the job, but it also failed to excel in any of our tests. If you're going to shell out for antivirus software, you can do better with your money.