The knives are out for Windows Defender, the basic anti-malware protection bundled with Windows 8: makers of rival antivirus products are lining up to criticise Microsoft's efforts to secure its operating system.
Windows 8 can be infected by 16 percent of the most common malware families, even with Windows Defender activated, according to tests by Romanian antivirus vendor Bitdefender.
The latest version of Microsoft's OS was compromised by 61 of 385 malware samples flung at it by BitDefender. In addition, one software nasty bypassed Windows Defender but crashed on execution, while another ran but was blocked by User Account Control (UAC), so no malicious payload was delivered.
Malware that successfully bypassed Windows Defender was capable of opening backdoors to allow hackers to remotely control the attacked x86 PC, intercepting keystrokes, stealing online gaming credentials, and more.
Bitdefender has a vested interest in talking up the security shortcomings of Windows 8 as it touts its own paid-for virus-zapping packages.
However, the company used malware collected over the last six months, which is not ideal: the test sample won't include every threat, according to Simon Edwards, technical director at Dennis Technology Labs. And every antivirus product misses some software nasties from time to time, despite what marketing departments' rhetoric would have us believe.
Bitdefender also tests malware by fetching a copy of the malicious code from an internal FTP server and executing it to see how far the malware progresses - as opposed to visiting a booby-trapped web page that attempts to comprise the PC, which is a more common method of infection. In theory, there should be little difference, but this methodology bypasses Windows Defender's SmartScreen that filters out phishing attacks and malware downloads when using Internet Explorer.
By way of defence, a Bitdefender analyst told El Reg: "We did not rely on tests over the internet because they are highly subjective and their success rate is – most of the times – dependent on the tech skills of the user operating the PC; our goal was to see how vulnerable the system without the user’s intervention is. In other words we’ve simulated a hapless user."
In addition, Bitdefender omitted to detect whether the successfully installed malware managed to survive a reboot on Windows 8. "Some of Windows 8’s security mechanisms should prevent Master Boot Records from being infected, which is one way the bad guys keep systems infected over time," Edwards explained.
"All vendors have a very strong motivation to demonstrate that Windows 8 is vulnerable and that alternatives to [Windows] Defender are necessary to provide the best security. I suspect that testing will show they are right, but there aren’t any good tests published yet, as far as I know, so they’re probably trying to race each other to show this themselves."
Microsoft Security Essentials in Windows 8
Security lab AV-Test, which sells analysis of malware to antivirus makers, also has reservations about Windows Defender following a preliminary review. The company drew its conclusions after throwing malicious code at Windows 7's Microsoft Security Essentials, which has been rebranded Windows Defender in Windows 8. AV-Test plans to formally review the effectiveness of Windows 8's built-in protection, and that offered by third-party security tools, in January.
"We saw rather similar results [to Bitdefender's] in our tests when we look at Microsoft Security Essentials, which is actually the new Windows Defender in Windows 8," the lab's chief exec Andreas Marx told El Reg.
"Microsoft offers a basic protection in their OS, so it's better than nothing, however the results are not good enough to replace existing free or paid security products."
Marx added that at least Windows Defender is capable of repairing the operating system if damaged. ®