Highly destructive Linux worm mutating

[InfoSec News <isn () C4I ORG>]

http://www.theregister.co.uk/content/8/17929.html

By: Thomas C Greene in Washington
Posted: 28/03/2001 at 06:12 GMT

The recently discovered Lion worm, which attacks Linux BIND (DNS)
servers, is turning out to be one nasty little package which leaves
infected victims with no choice but to re-format their entire systems
and rebuild from scratch.

We recently received a copy of a version which was released late last
week, thanks to a Register reader who prefers to remain anonymous. On
examining the package, we were immediately struck by how sophisticated
and functional it is, and yet how kiddie-friendly it is as well. It
obviously took considerable ingenuity and forethought to create, yet
requires almost none to deploy (a bit like SubSeven in that regard).

It's also exceptionally destructive, as we confirmed from examining
the logs of one victim who ran the Lionfind detection utility on his
infected system after having cleaned up manually as well as he could.
The number of files and directories Lion infects is nothing short of
staggering.

And it's mutating, so to speak. We had a word with Matt Fearnow at the
SANS Institute, who broke the news about Lion in an advisory posted
late last week. On Tuesday of this week, an upgraded version was
released, Fearnow told The Register.

This one includes a feature similar to one in the Ramen worm, which
altered the Web pages of hacked HTTP servers with the message "Hackers
looooooooooooove noodles," signed by the "RameN Crew."

The new Lion worm sets up an HTTP server on port 27374 and erects a
page bearing greetz from the Lion crew, Fearnow told us.

All versions (there are three now) are virtually idiot proof,
fire-and-forget tools. Each package contains a scanner which generates
random class B addresses searching for an opening on port 53. It then
queries the version, and if it finds it's vulnerable, runs a
well-known BIND 8 transaction signature (TSIG) handling code exploit,
and installs the t0rn rootkit.

It records all successful installations in an IP log file, which it
sends to the attacker via e-mail once every twelve hours.

At present the Lionfind utility, by William Stearns, will detect, but
not clean, the Lion worm. Stearns is working on a cleaner as well, but
considering the large amount of destruction Lion causes we're not
holding our breath. SANS's Fearnow says he hopes victims have a good
backup. "My best advice right now is just to re-format and
re-install," he confirmed.

Shoutz to the NIPC

We were hasty this week in our initial coverage, where we took a swipe
at the FBI's National Infrastructure Protection Center (NIPC) over a
Lion advisory bulletin of theirs which we deemed alarmist.

"The NIPC has received reports of an Internet worm named 'Lion' that
is infecting computers and installing distributed denial of service
(DDoS) tools on various computer systems," the bulletin warns.

That sounded like bollocks to us because the SANS advisory made no
mention of it, and because we could find no evidence of a DDoS tool in
the version of Lion which we evaluated; but actually, they're half
right.

According to SANS, the first version of Lion did come bundled with a
DDoS tool called Tribal Flood Network (tfn2k); though it does not, as
the NIPC strongly implies, install it automatically.

So the NIPC bulletin is a bit gaseous, but not as grossly flatulent as
we'd thought.

Chalk it up to experience. We lost respect for the NIPC when last
December they ran an alarmist bulletin with shades of terrorist
designs on US power utilities, but which actually involved nothing
more than a bunch of kids making use of an open FTP server to play an
interactive game, as we reported here.

We were ready to imagine them crying wolf again when in reality they
were only whispering wolf this time.

Sorry guys, our mistake.

ISN is hosted by SecurityFocus.com
---
To unsubscribe email LISTSERV () SecurityFocus com with a message body of
"SIGNOFF ISN".