%SysDir%\l32x.exe
%SysDir%\vxd32v.exe
dllxw.exe from the Starup Directory
3, Restore 'system.ini' to
[Boot]
Shell=explorer
4, Restart the computer
System Infection
Upon execution Dumaru.Z installs several copies of itself to the
computer:
- 'l32x.exe' to the Windows System Directory which is added
to the registry as
HKLM\Software\Microsoft\Windows\CurrentVersion\Run\load32
- 'dllxw.exe' is copied to the current users' Startup Directory.
- 'vxd32v.exe' to the Windows System Directory which is added to the
system.ini:
[Boot]
Shell=explorer vxd32v.exe
Email Propagation
Dumaru.Z uses its own SMTP engine to send emails. The SMTP engine performs
a direct name service lookup on the target domain so it does not depend
on the infected computer's email server settings.
To collect email addresses the worm recursively searches through all the
directories on the computer and looks for files that could contain email
addresses:
'.htm'
'.wab'
'.html
'.dbx'
'.tbb'
'.abd'
Going through the list of collected addresses Dumaru.Z sends emails with
infected attachments that have to following characteristics:
From: "Elene" <F*CKENSUICIDE@HOTMAIL.COM>
To: <user@targeted.somewhere>
Subject: Important information for you. Read it immediately !
Body:
Here is my photo, that you asked for yesterday.
Attachment: myphoto.zip
Payloads
Dumaru.Z - just like it's earlier variants - comes with capabilities
to steal sensitive user data:
- user's POP3 password
- clipboard data
- Protected Storage Data
- User credentials and key log data of visits to www.e-gold.com
The collected data is sent to a predefined email address.
Trojan Downloader
Dumaru.Z has a function that downloads a trojan from a predefined
location and places it to 'nvidia32.exe' to the Windows Directory.
The downloaded file is then executed to activate the trojan.
Detection
Detection in F-Secure Anti-Virus was published on January 26th, 2004 in
update:
Version=2004-01-26_01
Description:
Gergely Erdelyi and Katrin Tocheva, 25th of January, 2004
Technical Details:
Gergely Erdelyi, 26th of January, 2004
F-Secure Corporation
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