1. /
  2. Security Response/
  3. Downloader.Chekin


Risk Level 1: Very Low

June 23, 2003
February 13, 2007 12:02:49 PM
Also Known As:
TrojanDownloader.Win32.Checkin, TrojanDownloader.Win32.Checkin, Trojan.Download.Chekin
Trojan Horse
Systems Affected:
Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows XP

Downloader.Chekin is a Trojan Horse that appears to be a component of an adware application. This program periodically checks for new updates and launches them. The updates may come from any Web server on any IP address. A check is not made to verify their integrity prior to execution.

This Trojan is written in Microsoft Visual C++.

  • Virus definitions dated prior to June 24, 2003 may detect this as either Security Risk or Download.Trojan.
  • Sbsrch_v22.dll and Ttps.exe are additional files that have been found to be related to Downloader.Chekin. If the files are detected, delete them.
  • There have been reports that the file, Sifxinst.exe, is a file that the Trojan uses, and that this file, when run, creates the file, Owmngr.exe.
  • Virus definitions dated June 6, 2006 or earlier may detect this threat as Trojan.Download.Chekin.

Antivirus Protection Dates

  • Initial Rapid Release version June 24, 2003
  • Latest Rapid Release version June 24, 2014 revision 006
  • Initial Daily Certified version June 24, 2003
  • Latest Daily Certified version April 17, 2013 revision 016
  • Initial Weekly Certified release date June 25, 2003
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Threat Assessment


  • Wild Level: Medium
  • Number of Infections: 50 - 999
  • Number of Sites: 0 - 2
  • Geographical Distribution: Low
  • Threat Containment: Easy
  • Removal: Moderate


  • Damage Level: Medium


  • Distribution Level: Low
Note: On May 14, 2015, modifications will be made to the threat write-ups to streamline the content. The Threat Assessment section will no longer be published as this section is no longer relevant to today's threat landscape. The Risk Level will continue to be the main threat risk assessment indicator.
Writeup By: Scott Gettis

Search Threats

Search by name
Example: W32.Beagle.AG@mm
STAR Antimalware Protection Technologies
Internet Security Threat Report