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The Internet threat alert status is currently normal. At present, no major epidemics or other serious incidents have been recorded by Kaspersky Lab’s monitoring service. Internet threat level: 1

Trojan-Downloader.JS.Agent.sg

Detected Sep 26 2007 15:57 GMT
Released Sep 26 2007 15:57 GMT
Published Oct 21 2008 07:56 GMT

Technical Details
Payload
Removal instructions

Technical Details

This Trojan downloads other files via the Internet and launches them for execution on the victim machine. It is an HTML page which contains Visual Basic Script and Java Script. It is 677 bytes in size.


Payload

Once the Trojan is launched, it uses a vulnerability in the ActiveX component which has the unique system registry identifier shown below:

{A7F05EE4-0426-454F-8013-C41E3596E9E9}

The vulnerability (CVE-2007-4105) is present in the "DloadDS()" library "BaiduBar.dll". The Trojan attempts to load a file via this vulnerability. The file is located on the remote server shown below:

http://www1.*****joy.com/S368/cabS3682.exe

The file will be saved to the current user's Windows temporary directory and launched for execution.

At the time of writing, the link was not active.


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 all files from %Temporary Internet Files%.
  3. Disable the vulnerable ActiveX object (see How to stop an ActiveX control from running in Internet Explorer
  4. Empty the temporary directory (%Temp%).
  5. Update your antivirus databases and perform a full scan of the computer (download a trial version of Kaspersky Anti-Virus).

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Trojan-Downloader

Programs classified as Trojan-Downloader download and install new versions of malicious programs, including Trojans and AdWare, on victim computers. Once downloaded from the Internet, the programs are launched or included on a list of programs which will run automatically when the operating system boots up.

Information about the names and locations of the programs which are downloaded are in the Trojan code, or are downloaded by the Trojan from an Internet resource (usually a web page).

This type of malicious program is frequently used in the initial infection of visitors to websites which contain exploits.


Other versions

Aliases

Trojan-Downloader.JS.Agent.sg (Kaspersky Lab) is also known as:

  • JS/TrojanDownloader.Agent (Nod32)
  • Trojan.DL.Script.JS.Agent.lpv (Rising)