The number of random attacks against Linux-based systems has also declined during the last two years, report author Honeynet Project and the Honeynet Research Alliance said.

An unpatched Linux machine, running server builds of RedHat 9.0 or Suse 6.2, can now go three months before being compromised up from the previous level of 72 hours. The report said life expectancy for an unpatched Win32 machine appears to continue to decrease although the group did not provide hard figures.

Reasons cited for the difference included default installations of Linux becoming harder to compromise and the pervasive nature of Windows making it at larger target.