On Thu, 29 Jan 2004, Rishi Gangoly wrote:
The only way a program (virus) could infect the system
would be is if
a user actually saved an attachment to disk, then did a 'chmod 755
attachment' and then executed it by either double clicking it or
./attachment... Thus the user would have to be really dumb to infect
his computer. ;-)
A virus also needs to infect other binaries with itself. If run as a
regular user, the virus only has access to executables that are writable
by the current user. To infect the entire system, the virus would have
to be executed as root.
If root executes the virus, I'd say you've given root to the wrong
We need to contrast this with worms. Worms are capable of spreading
without human intervention, and yes, there have been linux worms in the
past. Typically, they would take advantage of well known holes in a
system's network security (remember l10n attacking rpcd, bind and
wuftpd) to gain access to that system. Once there, they'll install
themselves to be always executed, and then search for other hosts to
The only human intervention required is that the system be left open for
remote exploits like this.
We should remember that the first great Internet Worm was actually cross
platform. it worked on unix as well as vax systems.
Computer programmers never die, they just get lost in the processing.