Kaspersky Lab had a similar reaction. "[We] have analyzed the published material and concluded that the issue is only linked to certain features of [our] products," Kaspersky said in an emailed statement. "Kaspersky Lab products implement not only [kernel] hooks, but a wide range of technologies, including secure sandboxing and other methods of restricting suspicious kernel mode activity."
Huger confirmed that attackers would have to drop malware of some sort on the targeted machine in order to utilize the argument-switch strategy, and that there are "lots of easier ways to game anti-virus" than Matousec's technique.
"But that doesn't lesson the impact," Huger argued. "Actually, it would be really tricky to stop this, and gives attackers a strong opportunity to get around disk-based security."
Huger's greatest fear is that others take Matousec's findings, weaponize the argument-switch attack, and add it to one of the numerous underground exploit kits. "If someone packages this into an easy-to-use library, I think it'll be in play pretty quickly, with widespread adoption," said Huger. "Why wouldn't it?"
Several researchers with anti-virus companies, including Huger, noted that security software isn't defenseless against attempts to use argument-switch, in large part because attackers would still need to plant malware on a machine, and on-demand scanning would theoretically block any malicious downloads, at least of known threats.
"Any malware that we detect by our anti-virus will still be blocked, just like it always was," said F-Secure's Hypponen. "So the issue only affects new, unknown malware that we do not yet have a detection signature for."
Huger expects that attacks using argument-switch will target 32-bit Windows XP machines, both because that operating system continues to dominate the Windows ecosystem, and because it lacks the PatchGuard kernel protection that Microsoft added to 64-bit versions of XP in 2005, then later to 64-bit editions of Vista and Windows 7 .
"They may not be exclusive to Windows XP, but they'll be more prevalent under XP," Huger said.
Microsoft faced resistance from several anti-virus companies, notably Symantec and McAfee, before the release of Windows Vista. They complained that PatchGuard would prevent them from delivering key functions in their Vista-compatible products, including behavior-based virus detection, host-based intrusion prevention and software tamper protection. Microsoft relented and eventually made security application programming interfaces (API) available to allow vendors to do what they needed without accessing the kernel.
Those APIs first appeared in Windows Vista SP1 in 2008.
Matousec claimed that 64-bit versions of Windows boasting PatchGuard could be vulnerable in some instances. "[This] will work against all user mode hooks and it will also work against the kernel mode hooks if they are installed, for example, after disabling PatchGuard," Matousec's paper stated.
Microsoft did not immediately reply to a request for comment on Matousec's claim.