This IRC-based backdoor-worm was found on August 17th, 2005. It
is very similar to the IRCBot.es that was found 2 days earlier.
The backdoor provides unauthorised access to an infected computer
and also has the capability to spread to remote computers using
the PnP exploit on port 445.
F-Secure provides the special disinfection utility to eliminate
this malware infection. You can download this utility from our
ftp or web sites:
http://www.f-secure.com/tools/f-bot.zip
ftp://ftp.f-secure.com/anti-virus/tools/f-bot.zip
The unpacked version is available here:
http://www.f-secure.com/tools/f-bot.exe
ftp://ftp.f-secure.com/anti-virus/tools/f-bot.exe
Disinfection instructions can be found here:
http://www.f-secure.com/tools/f-bot.txt
ftp://ftp.f-secure.com/anti-virus/tools/f-bot.txt
If the infection is in a local network, please follow the
instructions on this webpage:
http://www.f-secure.com/v-descs/netdisinf.shtml
The backdoor's file is a PE executable file about 8 kilobytes
long, packed with MEW file compressor and patched with PE_Patch.
The code of backdoor is encrypted with a simple cryptoalgorithm.
When the backdoor's file is activated on a computer, it copies
its file to Windows System folder as WPA.EXE and then starts the
copied file as a service named 'Windows Product Activation',
described as follows:
Windows Product Activation is an anti-piracy technology designed
to verify that software products have been legitimately licensed.
If the backdoor fails to start its service, it tries to inject
its code into Explorer.exe process. When active, the backdoor
connects to the following server on port 18067:
ypgw.wallloan.com
Then backdoor joins an IRC channel called '#p4' using the
hardcoded password and creates a bot there. A remote hacker can
control a backdoor via a bot that it creates in the '#p4'
channel. A hacker can do any of the following:
* scan for vulnerable computers and spread to them using PnP exploit
* download and run files on an infected computer
* find files on local hard disks
* perform DDoS (Distributed Denial of Service) attack
* perform SYN and UDP flood
The backdoor has the ability to spread to remote computers using
the PnP exploit on port 445. Please see the following page for
detailed information on the vulnerability:
http://www.microsoft.com/technet/security/Bulletin/MS05-039.mspx
Detection for this malware was published on August 17th, 2005 in
the following F-Secure Anti-Virus updates:
[FSAV_Database_Version]
Version=2005-08-17_04
Technical Details:
Alexey Podrezov, August 17th, 2005;
F-Secure Corporation
