W32/Amca-A [Sophos]

Can we get this one added to the database , I’ve been having problems with it , They say its a low risk , I disagree with that it’s very hard to remove because u can remove it but then it comes back… And it is a high security risk for identity theft , So please add this to the definitions…

Discovered: 28 June 2007
Updated: 29 June 2007 7:59:49 AM
Also Known As: W32/Amca-A [Sophos]
Type: Worm
Infection Length: 376,832 bytes
Systems Affected: Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP

Once executed, the worm creates the following files:

* %System%\PAC.EXE
* %System%\lil11.dll
* %System%\scrrntr.dll
* %System%\KMON.OCX
* %System%\KTKBDHK3.DLL
* %System%\ACD.CMD
* %System%\ACD2.CMD

The worm then modifies the following registry entry:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon"Shell" = “Explorer.exe [ORIGINAL FILE NAME]”

Next, the worm spreads through network shares protected by weak passwords.

The worm then spreads through removable storage devices by creating the following file and setting the attributes to hidden:
[DRIVE LETTER]\activexdebugger32.exe

The worm also creates the following file so that it executes whenever the removable device is used on another computer:
[DRIVE LETTER]\Autorun.inf

The worm then opens a back door and allows a remote attacker to gain access to the compromised computer.

It may attempt to steal sensitive information from the compromised computer and send it to a remote attacker via email.

It may also attempt to download a file from an FTP site to the following location:

Note: At the time of writing, the downloaded file was not available.

Symantec Security Response encourages all users and administrators to adhere to the following basic security “best practices”:

* Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
* If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
* Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
* Enforce a password policy. Complex passwords make it difficult to ■■■■■ password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
* Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
* Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
* Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.

Writeup By: Asuka Yamamoto

W32/Amca-A Spyware Worm

* Summary
* Description
* Recovery
* Advanced

Prevalence: low Prevalencehigh
Name W32/Amca-A

* Spyware Worm

How it spreads

* Removable storage devices
* Network shares

Affected operating systems

* Windows

Side effects

* Allows others to access the computer
* Steals information
* Records keystrokes
* Installs itself in the Registry
* Leaves non-infected files on computer


* Trojan-Dropper.Win32.VB.pt
* Win32/VB.NLK worm


* Download virus identity (IDE) file

Protection available since 28 June 2007 13:52:28 (GMT)
Protection history

* Updated -4 July 2007 01:45:24 (GMT)
* Published -28 June 2007 13:52:28 (GMT)

Detected by All versions of Sophos Anti-Virus
Latest protection included in our products from August 2007 (4.20)
More information on IDE files

* What are IDE files?
* How to use IDE files
* Get the latest IDE files


* Summary
* Description
* Recovery
* Advanced

This section helps you to understand how it behaves

W32/Amca-A is a worm for the Windows platform.


* Summary
* Description
* Recovery
* Advanced

This section tells you how to remove the threat.

Please follow the instructions for removing worms.

* Summary
* Description
* Recovery
* Advanced

This section is for technical experts who want to know more.

W32/Amca-A is a worm for the Windows platform.

When installed W32/Amca-A attempts to share the local drives on the infected computers.
W32/Amca-A also spreads through removable storage devices, including floppy drives and USB keys. The worm attempts to create a hidden file Autorun.inf on the removeable drive and copy itself to the removeable drive with the hidden filename \activexdebugger32.exe.

W32/Amca-A also includes keylogger functionality that can be used for monitoring the user activity on the infected computers.

When first run W32/Amca-A copies itself to the Windows system folder and creates the following files:


The files activexdebugger32.exe, nesneler.exe and pac.exe are detected as W32/Amca-A.
The file kmox.ocx is detected as Troj/Frutitab-A.
The other files acd.cmd, acd2.cmd, scrrntr.dll, Ijl11.dll and ktkbdhk3.dll are clean and can safely be deleted.
The file mswinsck.ocx is a clean winsock control module used in Visual Basic applications.

The following registry entry is changed to run W32/Amca-A on startup:

HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

Hi Sargvik :slight_smile:

If you have a sample of the malware please :

  • email it to: malwaresubmit [ at ] avlab.comodo.com .
  • zip and password protect it with “infected” and include that information in the body.

Thank you m8 :slight_smile:

Greetz, Red.

Ah , I already deleted it , But it will probably come back… So until then i guess … Or if someone else gets infected with it please submit it to where Red posted , Thank You.

Hi, i am a Turkish software developer, this trojan which named activexdebugger32.exe is seen first in our country. I made a removal tool for this trojan its name is “dracula virüs temizleyici”. I will give you download link http://www.yazguven.com/draculavirustemiz.html

I write this program with C# language so you need Microsoft .NET Framework to work it, fot .NET Framework 2.0 the link; http://www.download.com/3000-10252_4-10726027.html?tag=dl.3

I never write for outside of Turkey about this trojan , you are the first :slight_smile:
good days without virus…