Trojan-Downloader.JS.Agent.mp

Technical Details

This Trojan downloads other files via the Internet and launches them for execution on the victim machine without the user’s knowledge or consent. It is a JavaScript script. It is 9656 bytes in size.

Payload

Once launched, the Trojan injects its code into the memory of processes which have the following unique identifiers in the system registry:

{BD96C556-65A3-11D0-983A-00C04FC29E30}
{BD96C556-65A3-11D0-983A-00C04FC29E36}
{AB9BCEDD-EC7E-47E1-9322-D4A210617116}
{0006F033-0000-0000-C000-000000000046}
{0006F03A-0000-0000-C000-000000000046}
{6e32070a-766d-4ee6-879c-dc1fa91d2fc3}
{6414512B-B978-451D-A0D8-FCFDF33E833C}
{7F5B7F63-F06F-4331-8A26-339E03C0AE3D}
{06723E09-F4C2-43c8-8358-09FCD1DB0766}
{639F725F-1B2D-4831-A9FD-874847682010}
{BA018599-1DB3-44f9-83B4-461454C84BF8}
{D0C07D56-7C69-43F1-B4A0-25F5A11FAB19}
{E8CCCDDF-CA28-496b-B050-6C07C962476B}

The Trojan uses vulnerabilities in “WinZIP FileView”, “QuickTime” and “WebViewFolderIcon” (all Active X components) and in the Msdds.dll MS Internet Explorer library in order to execute random code on the victim machine.

The Trojan also uses a vulnerability in the ActiveX XMLHTTP component to download a file from the following URL:

At the moment of writing, this link was not working.

The Trojan exploits a vulnerability in the ADODB.Stream component in order to save the downloaded file to the C: disk as “sys.<rnd>.exe”:

<rnd> are random Latin letters.

This file will also be saved to the Windows system directory as “~.exe”:

and as “cpu.exe”:

The file will also be saved to a directory one level higher than that where the original Trojan file is located as “tm.exe”.

The saved files are then launched for execution.

Removal instructions

If your computer does not have an up-to-date antivirus, or does not have an antivirus solution at all, follow the instructions below to delete the malicious program:

1. Delete the original Trojan file (the location will depend on how the program originally penetrated the victim machine).
2. Delete the following files:
   Ñ:\sys<rnd>.exe
   %System%\~.exe
   %System%\cpu.exe
   ../tm.exe
3. Update your antivirus databases and perform a full scan of the computer (download a trial version of Kaspersky Anti-Virus).