Internet security firm Finjan has released a 'sandbox' product to isolate executable file viruses just a week after an announcement by virus-writing group Cult of the Dead Cow that it will force improvements in virus security. Finjan's new SurfinShield software provides an artificial "sandbox" environment in which any executable file can be monitored in real-time. This offers an alternative to simply never opening any executable file received by email. A recent spate of malicious executable files such as ExploreZip.exe and Happy99.exe has prompted many security experts to recommend this as standard procedure. This will offer more protection from mobile code based viruses and hostile programs. Mobile code threats include not just executable files but Java Applets, Cookies, Plug Ins, Active X and JavaScript Visual Basic programs. The Cult of the Dead Cow, however, promised to release its own "sandboxing" software, CDC Protector, within the next few weeks in order to highlight deficiencies in current mainstream anti-virus software. Finjan furiously deny that they have been prompted to release their SurfinShield by this. "There's no way we could have developed this software in response to their claims," says Ron Moritz, CTO at Finjan. "Actually it's reassuring to see other people, including Cult of the Dead Cow, are interested in these sort of techniques. We have obviously just coincidentally been working on the same things." In May, Finjan signed a deal to supply SurfinShield with Intel motherboards. On its own, SurfinShield costs $125.