Downloader-AXA

This page shows details and results of our analysis on the malware Downloader-AXA

Download Current DAT: 6617

Threat Detail

Malware Type: Trojan

Malware Sub-type: Downloader

Discovery Date: 2006-06-21

Next Steps:

Overview
Characteristics
Symptoms
Method of Infection
Removal

Overview

Downloader serves as a downloading/ updating component for other malicious files. Generally it makes internet connections without user's knowledge.

Minimum DAT

4790 (2006-06-21)

Updated DAT

4790 (2006-06-21)

Minimum Engine

5.1.00

File Length

44,544

Description Added

2006-06-21

Description Modified

2006-06-22

Malware Proliferation

Characteristics

Upon execution, the trojan drops itself to:

%WINDIR%\systemer.exe ( 44544 bytes )

The following registry key is added.

hkey_local_machine\software\microsoft\windows\currentversion\run
\winsystem="%WINDIR%\systemer.exe"

The trojan retrieves a file list from the following URL.

www.cnphp5.com/[removed].txt

Then it attempts to download files in the list from the remote host.

Symptoms

Presence of the mentioned file
Presence of the mentioned registry key
Http connections to the mentioned host

Method of Infection

N/A. Downloaders are not viruses, and as such do not themselves contain any method to replicate. However they may themselves be downloaded by other viruses and/or Trojans to be installed on the user's system.

Many of these additionally are mass spammed by the author to entice people into double-clicking on them.

Alternatively they may be installed by visiting a malicious web page (either by clicking on a link, or by the website hosting a scripted exploit which installs the Downloader onto the user's system with no user interaction.

Removal

All Users:
Use current engine and DAT files for detection and removal.

Modifications made to the system Registry and/or INI files for the purposes of hooking system startup, will be successfully removed if cleaning with the recommended engine and DAT combination (or higher).

But in some particular cases, the following steps need to be taken.

Please go to the Microsoft Recovery Console and restore a clean MBR.

On Windows XP:

Insert the Windows XP CD into the CD-ROM drive and restart the computer.
When the "Welcome to Setup" screen appears, press R to start the Recovery Console.
Select the Windows installation that is compromised and provide the administrator password.
Issue 'fixmbr' command to restore the Master Boot Record
Follow onscreen instructions.
Reset and remove the CD from CD-ROM drive.

On Windows Vista and 7:

Insert the Windows CD into the CD-ROM drive and restart the computer.
Click on "Repair Your Computer".
When the System Recovery Options dialog comes up, choose the Command Prompt.
Issue 'bootrec /fixmbr' command to restore the Master Boot Record.
Follow onscreen instructions.
Reset and remove the CD from CD-ROM drive.