An unpatched PC is likely to last just four minutes on the internet before being attacked and compromised.

The time it takes for a PC to get itself owned varies by operating system and what activities a user engages in - but even allowing for this, putting an unpatched Windows PC directly onto the net in the hope that it downloads patches faster than it gets exploited give you "odds that you wouldn't bet on in Vegas", warns Lorna Hutcheson, a researcher at the SANS Institute's Internet Storm Centre (ISC).

The ISC maintains a survival time graph that gives an indication of how long a system might last on the internet before stumbling into the crosshairs of hackers, who routinely use automated tools to scan and commandeer vulnerable systems. Survival time, the ISC notes, has dropped markedly over the last two years, and is currently a fairly scary four minutes.

Security experts advise using a NAT (network address translation router) and personal firewall before connecting systems to the net on anything outside sacrificial systems. This best practice can create tensions between management, who want new systems up and running as quickly as possible, and security admins.

"More than once, I've dealt with a compromise of a system that was placed on the network before it was hardened," Hutcheson writes. "I got the same answer every time - 'We needed it working ASAP'. However, more time was spent playing clean up from it than if it was just done right the first time."

Thorsten Holz, of the German Honeynet Project, explains how exploits lead to system compromises. His analysis - complete with statistics and graphs - can be found here. ®
http://honeyblog.org/archives/193-Su...e-Fittest.html