Best Free Antivirus: Windows Defender vs. Avast | Maximum PC
Windows Defender uses the same pokey scan engine as Microsoft Security Essentials, and since there’s no easy way to schedule scans, it’s even more problematic. Running a full system scan with 30GB of data on a solid-state drive took 20 minutes with Windows Defender, and subsequent scans took just as long. That’s an indication that Windows Defender doesn’t skip over files that haven’t changed since the last time they were processed. Avast clocked five minutes and nine seconds to scan the same data, and though it also didn’t get any quicker during subsequent scans, it’s still significantly faster than Windows Defender. Plus, you can easily schedule scans in Avast to run during times when you’re not sitting at your PC, such as after-work hours (assuming you leave your PC on 24/7).
Windows Defender needed to pull out a win in this round to keep the race interesting, but it doesn’t have the legs to compete with Avast. Using our own collection of malware, Avast detected twice as many dirty files as Windows Defender, though that might have to do with the way each program counts individual files within an infected archive. In both cases, Malwarebytes detected infections that both Windows Defender and Avast missed. However, Avast is better at detecting zero-day threats and adds a second layer of protection through its automatic sandbox mode, which Windows Defender lacks. Finally, we’re a little wary given that Microsoft’s antimalware engine is having trouble passing certification with AV-Test (www.av-test.org), a well-known independent testing laboratory. All things considered, this crucial round goes to Avast.
Try saving this as an .exe file with Windows Defender.
Avast wins this bout by taking three of the five categories and tying in another, though it’s not quite as lopsided as it appears. Windows Defender, while not as fully featured as Avast, is capable of blocking common threats, and it doesn’t put a drain on system resources. Avast’s army of defenses is just bigger and better trained to spot danger from more places, like IM clients. It also has a bigger arsenal of weapons.
It's from Eicar virus testing:
Avast wouldn't even allow it TO be saved.
Sent it straight to the virus vault.