Disinfection instructions can be found here:
ftp://ftp.f-secure.com/anti-virus/tools/f-korgo.txt
System administrators who are using F-Secure Policy Manager,
can distribute the tool as a JAR package automatically to all
workstations.
System administrators can download the JAR version from:
http://www.europe.f-secure.com/tools/f-korgo.jar
ftp://ftp.f-secure.com/anti-virus/tools/f-korgo.jar
The worm's file is a PE executable 9343 bytes long packed with a
modified UPX file compressor. The unpacked file's size is about
19 kilobytes.
When the worm's file is run, it first deletes the FTPUPD.EXE
file. Then the worm creates a mutex with the "uterm13" name. This
is done to avoid loading multiple copies of the worm into memory.
Next, the worm deletes Registry key values and terminates
processes with any of the following names:
Windows Security Manager
Disk Defragmenter
System Restore Service
Bot Loader
SysTray
WinUpdate
Windows Update Service
avserve.exe
avserve2.exeUpdate Service
MS Config v13
The key values are deleted from the following Registry key:
[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
After that the worm installs itself to system and creates a
startup key for its file in the Registry. The worm's file is
copied to Windows System folder with a randomly generated name.
The following Registry key is then created:
[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
"Windows Update" = "%WinSysDir%\<random>.exe"
where WinSysDir represents Windows System directory name and
<random> represents random characters. The name of the worm's
file can be for example 'sjsudf.exe'.
Additionally the worm can create the following Registry key
values:
[HKLM\Software\Microsoft\Wireless]
"ID"
"Client"
The worm tries to start its spreading routine as a remote thread
of Windows Explorer. If this fails, the worm starts the spreading
thread directly.
Unlike its previous variants, the worm does not connect to IRC,
does not create an IDENT server on port 113 and does not start a
backdoor on port 3067. Instead, the worm periodically connects to
several websites (sometimes, depending on an internal flag, with
a specially constructed URL) and reads a file from there. If the
file's data does not contain 'zer0' string, the worm waits and
re-connects again. But if the file contains 'zer0' string, the
worm downloads an executable file from that website to Windows
System folder and runs it. It should be noted that the worm
performs a secure authentication before the file is downloaded.
Here's the list of websites that the worm tries to connect to:
mazafaka.ru
xware.cjb.net
citi-bank.ru
konfiskat.org
adult-empire.com
parex-bank.ru
kidos-bank.ru
crutop.nu
kavkaz.ru
color-bank.ru
master-x.com
asechka.ru
trojan.ru
padonki.org
f*ck.ru
goldensand.ru
filesearch.ru
lovingod.host.sk
www.redline.ru
cvv.ru
hackers.lv
fethard.biz
Additionally the worm can listen on a random TCP port.
The worm spreads to remote computers using LSASS vulnerability.
It contacts remote computers on TCP port 445, exploits the
vulnerability and copies its file to a remote system.
Detection of Korgo.P/Padobot.G variant was published on June
17th, 2004 in the following F-Secure Anti-Virus update:
[FSAV_Database_Version]
Version=2004-06-17_03
Technical Details:
Alexey Podrezov; June 18th, 2004;
Description Updated:
Alexey Podrezov; June 23rd, 2004;
F-Secure Corporation
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