Eng
  1. Skip to navigation
  2. Skip to content
  3. Skip to sidebar


Trojan-Downloader:W32/Exchanger


Aliases:


Trojan-Downloader:W32/Exchanger
Trojan-Downloader.Win32.Exchanger

Malware
Trojan-Downloader
W32

Summary

Trojan-Downloader:W32/Exchanger variants download additional malicious software onto the infected system.



Disinfection & Removal

To manually remove a Trojan-Downloader:W32/Exchanger infection, perform the following steps:

  • Open the Windows Task Manager by pressing the Ctrl + Alt + Delete keys and click the Task Manager button.
  • From the list of running processes, find CbEvtSvc.exe and then click the End Process button.
  • You may close the Task Manager once the malicious process is terminated.
  • From the Windows Start Menu, select Run, type regedit into the "Open:" field and then click OK.
  • From the Registry Editor, locate and delete the following keys if present:
    • HKLM\SYSTEM\CurrentControlSet\Services\CbEvtSvc
    • HKLM\SYSTEM\ControlSet001\Services\CbEvtSvc
    • HKLM\SYSTEM\ControlSet002\Services\CbEvtSvc
    Note: HKLM equals HKEY_LOCAL_MACHINE
  • Delete the file called CbEvtSvc.exe located in the C:\WINDOWS\system32\ folder.


Technical Details

Once the trojan is executed it copies itself into the "system32" folder and starts itself from there as a service.The trojan also creates Windows registry entries to ensure that it is started every time the computer is started.Once running, Exchanger variants will attempt to contact a remote server in order to relay information about the infected machine. The server will reply with a list of URLs that point to malicious files to be downloaded.


File System Changes

Creates these files:

  • %windir%\system32\CbEvtSvc.exe

Process Changes

Creates these processes:

  • %windir%\system32\CbEvtSvc.exe

Registry Modifications

Sets these values:

  • HKLM\System\CurrentControlSet\Services\CbEvtSvc Type = 00000010 Start = 00000002 ErrorControl = 00000001 ImagePath = %SystemRoot%\System32\CbEvtSvc.exe -k netsvcs DisplayName = CbEvtSvc ObjectName = LocalSystem Opt =
  • HKLM\System\CurrentControlSet\Services\CbEvtSvc\Security Security = \x01\x00\x14\x80\x90\[...]

Creates these keys:

  • HKLM\System\CurrentControlSet\Services\CbEvtSvc
  • HKLM\System\CurrentControlSet\Services\CbEvtSvc\Security






Submit a sample




Wondering if a file or URL is malicious? Submit a sample to our Lab for analysis via the Sample Analysis System (SAS)

Give And Get Advice




Give advice. Get advice. Share the knowledge on our free discussion forum.

Scan and clean your PC




F-Secure Online Scanner will scan and clean your PC in just a few minutes for free