Threat description


Category: Malware
Type: Worm
Platform: Solaris
Aliases: Worm:Solaris/Wanuk.A, Worm:Solaris/Wanuk.A


This malware uses a known vulnerability in Sun Solaris, the Sun Solaris TelNet Remote Authentication Bypass vulnerability. It uses adm and lp as its username.


Automatic action

Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.

More scanning & removal options

More information on scanning and removal options available in your F-Secure product can be found in the Help Center.

You may also refer to the Knowledge Base on the F-Secure Community site for further assistance.

Network Disinfection

For general instructions on disinfecting a local network infection, please see Eliminating A Local Network Outbreak.

Technical Details

Upon execution, this malware drops the following files on /var/adm/sa/.adm:

  • .i86pc - worm component for Intel-based processors
  • .sun4 - worm component for Sparc-based processors
  • .lp-door.i86pc - backdoor component for Intel-based processors (Backdoor:Solaris/Wanukdoor.A)
  • .lp-door.sun4 - backdoor component for Sparc-based processors (Backdoor:Solaris/Wanukdoor.A)

Note: These files will be dropped regardless of the processor being used by the infected machine.This malware executes the following command "uname -m" to check the processor type of the targeted machine. If the return value is 14h, it is Intel-based processor, if it is 15h, it is Sparc-based processor. The following dropped files will be either a copy of .i86pc or .sun4: It will drop a copy and use one of the following filenames in /var/adm/sa/.adm:

  • devfsadmd
  • svcadm
  • cfgadm
  • kadmind
  • zoneadmd
  • sadm
  • sysadm
  • dladm
  • bootadm
  • routeadm
  • uadmin
  • acctadm
  • cryptoadm
  • inetadm
  • logadm
  • nlsadmin
  • sacadm
  • syseventadmd
  • ttyadmd
  • consadmd
  • metadevadm

And with one of the following filenames in /var/spool/lp/admins/.lp:

  • lpshut
  • lpsystem
  • lpadmin
  • lpmove
  • lpusers
  • lpfilter
  • lpstat
  • lpd
  • lpsched
  • lpc

Lastly in /var/spool/lp/admins/.lp, a copy of the backdoor component (Backdoor:Solaris/Wanukdoor.A)

  • .lp-door.i86pc - if the processor type is Intel
  • .lp-door.sun4 - if the processor type is Sparc

Autostart Mechanism

This malware creates the following cron job:

echo 10 1 * * * (cd %s  cd %s  [ -x %s ]  PATH=. %s) /dev/null .crontab  

The above piece of code was used twice. It was used for the .adm files and .lp files. It can be rewritten as:

echo 10 1 * * * (cd /var/adm/sa/ 
 cd .adm 
 [ -x {file dropped} ] 
 PATH=. {file dropped}) /dev/null 2
  .crontab  And  echo 10 1 * * * (cd /var/spool/lp/admins/.lp 
 cd .lp 
 [ -x {file dropped} ] 
 PATH=. {file dropped}) /dev/null 2 1  .crontab

This means that it will create a cron job that will start every day at 1:10am. It will execute the file dropped in /var/adm/sa/.adm or /var/spool/lp/admins/.lp and will be added to the PATH. "/dev/null 2 1" this code makes the execution in the terminal without any output.


This malware uses a known vulnerability in Sun Solaris, the Sun Solaris TelNet Remote Authentication Bypass vulnerability. It uses adm and flp as its username.


Every 13th day of the month, this malware attempts to send any of the following messages using /usr/sbin/wall:

Otherwise, it will execute the following commands and process the output to possibly get a list of targeted IP addresses:

/usr/sbin/ifconfig -u4a /usr/bin/netstat -f inet -rn   

Note: It parses the output using the following strings:

  • netmask
  • inet
  • broadcast

Description Created: 2007-03-04 15:04:16.0

Description Last Modified: 2007-03-05 03:18:19.0


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