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


Detected Mar 19 2010 09:33 GMT
Released Mar 19 2010 14:05 GMT
Published Dec 22 2010 10:18 GMT

Technical Details
Removal instructions

Technical Details

This Trojan opens different web sites without the knowledge or consent of the user. It is a JavaScript scenario. It is 417 bytes in size.


When an infected page is opened, the Trojan decrypts itself using Java Script tools and launches its malicious code for execution. The HTML document that opens contains an embedded hidden frame in which the Trojan attempts to open the following web resource:


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 (its location will depend on how the program originally penetrated the victim machine).
  2. Empty the Temporary Internet Files folder, which may contain infected files (How to delete infected files from Temporary Internet Files folder?).
  3. Update your antivirus databases and perform a full scan of the computer (Download a trial version of Kaspersky Anti-Virus).

Bookmark and Share

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


Trojan-Downloader.JS.Iframe.bzn (Kaspersky Lab) is also known as:

  • Mal/Iframe-F (Sophos)
  • JS.Iframe.Gen.19 (VirusBuster)
  • JS:IFrame-Y [Trj] (AVAST)
  • Trojan-Downloader.JS.Iframe (Ikarus)
  • NseCheckFile2() returned 0x00010018 (Norman)
  • JS.Iframe.Gen.19 (VirusBusterBeta)