These 12 applications aren't afraid to mix it up with spyware, viruses, or keyloggers. But some will stab your PC's malware in the throat, and some will get shot in the back. Which is which?

Gone are the days when viruses and malicious software displayed taunting messages or erased your files. These days it's all about the money, baby! Malware writers backed by organized crime are constantly working on schemes to steal personal information or raid your bank accounts online. A recent Consumer Reports survey says that in the last two years users have lost nearly $8.5 billion to "viruses, spyware, and phishing schemes." And that doesn't even count 2.1 million computers thrown out and replaced because the malware mess was unbearable.

When cyber-Nazis are massing for an attack at your borders, or when they've already invaded, you need some hard-nosed defenders working for your protection. Fortunately you don't have to train up a gang of convicted murderers to do the job. You can choose from the dozen malware marauders below. Their skills varysome are better at wiping out snipers and sneaks, others specialize in defense. Some are highly skilled, others may let the side down. Choose wisely and you'll gain a powerful defender, whatever your budget.



Ad-Aware is steadily improving. Spyware removal in this version is excellent, in part due to the new antivirus scanner. The product's real-time protection, however, is years out of date.



The idea is great: You plug the USB stick into a computer and clean up the malware problem with no installation required. But it's just not effective. In fact, in my testing, Trojan horses infected the stick, turning it into a malware delivery device! You'd be better off carrying a USB key with installers for the better free anti-malware products.



avast!'s virus protection isn't far behind that of the top antivirus products. It removes spyware nearly as well as the top antispyware, and its resident protection against new infestation is excellent. This is some seriously impressive protection, considering that it's free for personal use.



AVG Anti-Virus Free 8.0's protection is nearly as good as that of the top for-pay antivirus and antispyware products. Scanning of search links for dangerous pages is an added bonus. And as long as it's for your personal home use, it's free!



This version has improved its malware-removal accuracy from abysmal to dismal. It still offers no real-time protection and attempts to remove valid programsand now you have to pay for malware removal. Stay away.



NovaShield AntiMalware aims to block malware by detecting malicious behaviors. In testing it was a near-total flop, missing most of the malware on my tests and identifying several valid utilities as "high risk" threats. And it rendered two test systems unusable. There's no reason to buy this when you can get ThreatFire for free.

SpyEraser 2

While it doesn't kill off innocent programs as its predecessor did, SpyEraser 2 just isn't effective at removing malicious software. It's even worse at keeping malware out of a clean system. This program still has a long way to go.

Spyware Doctor with AntiVirus 6

The latest Spyware Doctor doesn't look any different, but its ability to remove malware and keep clean systems clean is better than ever. It takes a while to install, and scanning is slow on a badly infested system. But it's worth the wait. This is powerful protection!

STOPzilla 5.0

STOPzilla has a cute name, but it costs more than the best standalone antispyware programs and does less. Yes, it does offer some bonus features for Internet Explorer, but they're things that IE already does...and does better.

ThreatFire 3.5

Standard signature-based antivirus/antispyware programs can't recognize a threat that's too new to have a signature. ThreatFire 3.5 relies strictly on advanced behavior analysis to identify and remove both known and unknown threats. This free utility will be an excellent complement to your existing protection!

Vipre Antivirus + Antispyware 3.1

Vipre's overall scores are almost as high as those of Spyware Doctor with AntiVirus 6. It detected every malware sample and removed most. It did, however, leave a couple of rootkits running. But it's still more effective than almost all of its competition.

Webroot AntiVirus with AntiSpyware and Firewall

This impressive app's multiple layers of protection prevent installation of most malware, and it did a good job of cleaning up malware-infested systems. Webroot has even thrown in a new firewall, as the name implies. This addition is a bit of a mixed bag, but it doesn't add to the price tag, and you can shut it off if you don't like it.