Backdoor:W32/Bifrose.EE

Classification

Category :

Malware

Type :

Backdoor

Aliases :

Bifrose.EE, Bifrose, Backdoor.Win32.Bifrose.ee

Summary

Bifrose is a stealthy backdoor that allows remote access to infected machine. It is usually installed to system by a trojan dropper.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

Installation to system

When run, the backdoor copies itself under %SysDir% directory using the name 'syspare.exe'. It installs the following registry keys to make sure it will be executed next time the system is started:

[HKLM\Software\Microsoft\Windows\CurrentVersion\Run]
"syspare.exe" = "syspare.exe"
[HKLM\Software\Microsoft\Active Setup\Installed Components\{9B71D88C-C598-4935-C5D1-43AA4DB90836}]
"stubpath.exe" = "syspare.exe"
 

The backdoor also creates the following registry key for storing information:

[HKLM\Software\Wget]

Backdoor

After the installation, Bifrose tries to locate a running web browser and inject code into it. The injected code is the actual backdoor. The backdoor starts to communicate with the server part using specially crafted HTTP queries. The server can instruct the backdoor to execute the following actions:

Basic file operations (copy, delete, rename, find, execute)
Download/upload files
Process operations (list, kill)
Registry operations (create/delete keys/values)
Create screenshots of the desktop