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[Hilos de Discusión] [Fecha] [Tema] [Autor]> On Fri, 23 Mar 2001, The SANS Institute wrote: > > > ALERT! A DANGEROUS NEW WORM IS SPREADING ON THE INTERNET > > > > March 23, 2001 7:00 AM > > > > Late last night, the SANS Institute (through its Global Incident > > Analysis Center) uncovered a dangerous new worm that appears to be > > spreading rapidly across the Internet. It scans the Internet looking > > for Linux computers with a known vulnerability. It infects the > > vulnerable machines, steals the password file (sending it to a > > China.com site), installs other hacking tools, and forces the newly > > infected machine to begin scanning the Internet looking for other > > victims. > > > > Several experts from the security community worked through the night to > > decompose the worm's code and engineer a utility to help you discover > > if the Lion worm has affected your organization. > > > > Updates to this announcement will be posted at the SANS web site, > > http://www.sans.org > > > > > > DESCRIPTION > > > > The Lion worm is similar to the Ramen worm. However, this worm is > > significantly more dangerous and should be taken very seriously. It > > infects Linux machines running the BIND DNS server. It is known to > > infect bind version(s) 8.2, 8.2-P1, 8.2.1, 8.2.2-Px, and all > > 8.2.3-betas. The specific vulnerability used by the worm to exploit > > machines is the TSIG vulnerability that was reported on January 29, > > 2001. > > > > The Lion worm spreads via an application called "randb". Randb scans > > random class B networks probing TCP port 53. Once it hits a system, it > > checks to see if it is vulnerable. If so, Lion exploits the system using > > an exploit called "name". It then installs the t0rn rootkit. > > > > Once Lion has compromised a system, it: > > > > - Sends the contents of /etc/passwd, /etc/shadow, as well as some > > network settings to an address in the china.com domain. > > - Deletes /etc/hosts.deny, eliminating the host-based perimeter > > protection afforded by tcp wrappers. > > - Installs backdoor root shells on ports 60008/tcp and 33567/tcp (via > > inetd, see /etc/inetd.conf) > > - Installs a trojaned version of ssh that listens on 33568/tcp > > - Kills Syslogd , so the logging on the system can't be trusted > > - Installs a trojaned version of login > > - Looks for a hashed password in /etc/ttyhash > > - /usr/sbin/nscd (the optional Name Service Caching daemon) is > > overwritten with a trojaned version of ssh. > > > > The t0rn rootkit replaces several binaries on the system in order to > > stealth itself. Here are the binaries that it replaces: > > > > du, find, ifconfig, in.telnetd, in.fingerd, login, ls, mjy, netstat, > > ps, pstree, top > > > > - "Mjy" is a utility for cleaning out log entries, and is placed in /bin > > and /usr/man/man1/man1/lib/.lib/. > > - in.telnetd is also placed in these directories; its use is not known > > at this time. > > - A setuid shell is placed in /usr/man/man1/man1/lib/.lib/.x > > > > DETECTION AND REMOVAL > > > > We have developed a utility called Lionfind that will detect the Lion > > files on an infected system. Simply download it, uncompress it, and > > run lionfind. This utility will list which of the suspect files is on > > the system. > > > > At this time, Lionfind is not able to remove the virus from the system. > > If and when an updated version becomes available (and we expect to > > provide one), an announcement will be made at this site. > > > > Download Lionfind at http://www.sans.org/y2k/lionfind-0.1.tar.gz > > > > > > REFERENCES > > > > Further information can be found at: > > > > http://www.sans.org/current.htm > > http://www.cert.org/advisories/CA-2001-02.html, CERT Advisory CA-2001-02, > > Multiple Vulnerabilities in BIND > > http://www.kb.cert.org/vuls/id/196945 ISC BIND 8 contains buffer overflow > > in transaction signature (TSIG) handling code > > http://www.sans.org/y2k/t0rn.htm Information about the t0rn rootkit. > > The following vendor update pages may help you in fixing the original BIND > > vulnerability: > > > > Redhat Linux RHSA-2001:007-03 - Bind remote exploit > > http://www.redhat.com/support/errata/RHSA-2001-007.html > > Debian GNU/Linux DSA-026-1 BIND > > http://www.debian.org/security/2001/dsa-026 > > SuSE Linux SuSE-SA:2001:03 - Bind 8 remote root compromise. > > http://www.suse.com/de/support/security/2001_003_bind8_ txt.txt > > Caldera Linux CSSA-2001-008.0 Bind buffer overflow > > http://www.caldera.com/support/security/advisories/CSSA-2001-008.0.txt > > http://www.caldera.com/support/security/advisories/CSSA-2001-008.1.txt > > > > This security advisory was prepared by Matt Fearnow of the SANS > > Institute and William Stearns of the Dartmouth Institute for Security > > Technology Studies. > > > > The Lionfind utility was written by William Stearns. William is an > > Open-Source developer, enthusiast, and advocate from Vermont, USA. His > > day job at the Institute for Security Technology Studies at Dartmouth > > College pays him to work on network security and Linux projects. > > > > Also contributing efforts go to Dave Dittrich from the University of > > Washington, and Greg Shipley of Neohapsis > > > > Matt Fearnow > > SANS GIAC Incident Handler > > > > If you have additional data on this worm or a critical quetsion please > > email lionworm en sans org > > > > ---------------------------------------------------------------------- > > gpg: ATENCIÓN: ¡se está usando memoria insegura! > > gpg: Firma creada el vie 23 mar 2001 08:34:15 CST usando clave DSA ID A1694E46 > > gpg: Imposible comprobar la firma: Clave pública no encontrada > > ---------------------------------------------------------------------- > > > --------------------------------------------------------- para salir de la lista, enviar un mensaje con las palabras "unsubscribe ayuda" en el cuerpo a majordomo en linux org mx