More often than not I'll be writing about the security problems facing Windows XP users, such as when I recently reported how a large number of enterprises are still running XP SP2 machines which will shortly stop being supported by Microsoft in terms of security updates, hotfixes and the like. So imagine my surprise, at the same time that Microsoft reminds us that it's the end of the line for Windows XP netbooks, to finally get hold of a story about Windows XP being good for security.

OK, so the report from the Webroot Threat Blog is a pretty damn specific one, relating just to a single Trojan downloader executable, but it's a Windows XP good security news story nonetheless.

It would seem that researchers at the security labs have caught the first Trojan, a variant of the Tacticlol downloader, which simply refuses to execute under Windows XP. A new spam campaign was distributing the Trojan and it executed as expected under both Windows Vista and Windows 7, but repeated tests on both virtual and real machines, with various levels of patching, have determined that the thing just will not run in an XP environment.

So there you have it, Windows XP users are safe from a Trojan downloader which kick-starts what Webroot describes as a "devastating malware infection" while users of the more secure Windows versions are vulnerable.

The really interesting thing for me is the notion that this could signal that the bad guys are giving up on Windows XP, at least as a platform for malware executables.