Classification

Category :

Malware

Type :

-

Aliases :

Petala, Backdoor.Petala

Summary

Petala backdoor (hacker's remote tool) was first found on 28th of September 2003. The backdoor provides a limited access to an infected system for remote hackers. The backdoor originate from Brasil.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

The backdoor is written in Visual Basic. Its file is 331 kilobytes long and has VB P-Code instead of normal Assembly instructions.

Techical details

When the backdoor's file is run, it installs itself to system. The backdoor copies itself to Windows folder as WINDATA.EXE file and to Windows System folder as MSJIS.EXE file. The backdoor creates startup keys for both these files in System Registry:

[HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\RUN]
"Microsoft Network Registry Control" = "%windir%\system\msjis.exe"
[HKEY_USERS\S-1-5-21-484763869-746137067-854245398-1003\Software\Microsoft\Windows\CurrentVersion\Run]
"Environ Monitor" = "%windir%\system\msjis.exe"
[HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\RUN]
"Microsoft Network Control" = "%windir%\windata.exe"
[HKEY_USERS\S-1-5-21-484763869-746137067-854245398-1003\Software\Microsoft\Windows NT\CurrentVersion\Windows\Run]
@ = "%windir%\windata.exe"

The backdoor can also modify WIN.INI file to make its files start during every Windows session.

The backdoor can create the following files in Windows folder:

msjet.sys
navrs.sys
regbck.sys

The backdoor replaces SCRIPT.INI file of mIRC client with its own one. The new file instructs an IRC client to send the following message to all users joining a channel where an infected person is present:

Tranforme seu WINDOWS numa super estacao de trabalho interligada
24h na internet com os melhores servicos gr¡tis. Desde
televis£o, cinema, ate jogos e supermercado, locadora, acougue,
farm¡cia de todo brasil. Algo realmente nunca visto antes. E
tudo com um simples update e com a garantia da microsoft.
Confira:

We believe that the backdoor's author wanted the backdoor to spread through IRC networks, but this functionality was not completed for some reason.

The backdoor can be controlled using an IRC bot. Additionally the backdoor has a built-in FTP server and mail relay. A hacker can do the following actions using the backdoor:

Login to backdoor
Change bot's nick
Join or part a channel
Send text message
Set channel mode
Start file
Delete file
Copy file
Send SPAM
Change IDENT
Give or take voice (prefered user)
Give or take op (channel operator)
Ban or unban user
Ignore user
Uninstall backdoor
Send URL
Get process list
Kill specified process
List files on an infected hard drive
Start frp server

Payload

The backdoor kills the following files:

%windir%\menu iniciar\programas\iniciar\wd.exe
%windir%\Start Menu\Programs\StartUp\wd.exe
%sysdrv%\Documents And Settings\All Users\Menu Iniciar\Programas\Inicializar\wd.exe

where %sysdrv% is system drive and %windir% is Windows folder.

The backdoor deletes files and terminates processes with the following names:

vsmon.exe
minilog.exe
zapro.exe
avgserv.exe
symtray.exe
wingate.exe
persfw.exe
vsstat.exe
vshwin32.exe
webscan.exe
rulaunch.exe
mcshield.exe
wg2eng95.exe
nprotect.exe
avgserv9.exe
pstores.exe
avgcc32.exe
wg3eng9x.exe
navapw32.exe
wengmon.exe
cjinject.exe
ccevtmgr.exe
navapw32.exe
poproxy.exe
proxy.exe
csinsm32.exe
monwow.exe
cmgrdian.exe
avconsol.exe
avsynmgr.exe