.Net may lead to fewer viruses

Virus Bulletin Antivirus vendors will have to significantly redesign their products in order to address risks of malicious code arising from the release of Microsoft's .Net platform.

The change of computing model to Web services that comes with .Net will almost undoubtedly create fresh infection mechanisms for virus writers to exploit.

In particular .Net will create new files called Common Language Runtime (CLR), which contain executable code known as Microsoft Intermediate Language (MSIL), which vendors agree is not yet addressed by AV products.

Eric Chien, of Symantec, said that the security models to be introduced with .Net, may actually result in a drop of the number of new incidents of malicious code, so the issue is one of different vectors of infection coming into play.

Richard Wang, a virus analyst at Sophos, said the challenge for antivirus developers is to viral code would not need to be in a file, so a .Net virus might contain only something that specifies where malicious code comes from. This means AV protection must, in some way, inspect the remote code.

Viruses that infect .Net binaries, Trojans written in .Net languages and malicious code taking advantages of .Net services are all possible.

Because MSIL is designed as a cross platform language along the lines of the Java model, it might allow "viruses to propagate to operating systems that were previously considered low risk", according to Chien. MSIL can be thought of as a compiler for whatever hardware platform .Net services are running on.

While technically possible, Microsoft has yet to announce a common language runtime for Unix or Linux and viruses written in MSIL and CLR-unaware viruses pose a much lower risk.

The issue of .Net and malicious code is an academic question for now, with widespread use of .Net products and services maybe five years away, but its still interesting the visit the subject because Web services represent the future of IT, at least according to most major vendors.

The jury is still out on whether this represents a more, or less, secure world. ®