A phishing scam emulating the Windows Update Service hit Australia yesterday, designed to not only emulate the update page perfectly, but circumvent current antivirus, spyware and adware programs.
The spam e-mail directs users to a page that pulls graphics from the Microsoft.com Web site and then recreates the page asking users to download a Windows update that is actually a malicious .exe file.
Director of SurfControl, Charles Heunemann, said the company discovered the virus late last night and that current heuristics and signatures used by core antivirus vendors are not picking up the malicious code.
"We are still trying to get to the bottom of it," Heunemann said.
"It is not a malicious attack for network resources but appears to send a message to the Internet advertising itself as a zombie machine - we think the .exe file pulls other code to turn the machine into a spamming server.
"The actual e-mail looks like a Microsoft e-mail but I don't think it is the practice for Microsoft to ask users to update their operating system by launching a link from an e-mail."
The virus, titled Wupdate-20050401, installs an executable file into the Windows directory and adds a startup service. When it is running the program takes up 100 percent of the CPU power, controlling the CPU by forcing it to perform continuous processes.
Microsoft security product manager Ben English said this is just one of many scams they are currently monitoring, adding that it is not unique.
"There are effective defences against these types of scams and we advise users to follow some simple guidelines," English said.
"Microsoft is aware of the SurfControl notice regarding the spoofing scam of Windows update and our advice to customers remains the same.
"Microsoft never attaches software updates to our security e-mail notifications; we never send notices about security updates or incidents until after we publish information about them on our Web site and if you suspect that an e-mail message is not legitimate, do not click any hyperlinks within it."
Sophos' Asia Pacific head of technology, Paul Ducklin, was aware of the program in question and said despite all the technology in the world, education and informed decisions by users will always be the best resort to stopping malware.
"Even if all other defences are down, with Trojan malware if a person doesn't click on it, it won't work - they all involve, to some extent, collaboration with users," Ducklin said.
"Three ways to block them include having software to prevent a suspicious program, using programs at the gateway to block .exe files and of course user education and information."