Ursnif, Trojan:W32/Ursnif, Trojan.Spy.Ursnif, Trojan.GenericKD.30550163, Gozi, ISFB


Ursnif steals system information and attempts to steal banking and online account credentials.


Automatic action

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.

Find out more

Knowledge Base

Find the latest advice in our Community Knowledge Base.

User Guide

See the user guide for your product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details


Upon execution, Ursnif checks for the presence of any virtual or debugging environments; if found, it will show a fake alert message box with the text, "Error Initializing Client App!". It also performs process hollowing on svchost.exe or explorer.exe and injects a dll file (client.dll) based on the system enviornment (whether it is 32- or 64-bit).

Afterwards, it tries to steal multiple pieces of information from the system and store them in a file. It then connects to a malicious command and control (C&C) server.

Infection Vector

Ursnif is typically encountered when the user inadvertently opens a malicious file attachment that arrives via a spam email message.

Files Added

  • Create a copy of itself at "%appdata%\[Random_Folder]\[Dropped_Filename].exe" where "Dropped_Filename" is a combination of strings taken from %system32% directory filenames.
  • Creates a batch file at "%temp%\[Random_Folder]\[Random_File].bat" to execute and delete itself.
  • Creates a storage file at %temp%\[Random_Hex].bin to store the stolen data. Stolen data is in cab file format, which is created by executing makecab.exe. The storage file contains the following information:
    • Installed Device Drivers - Collected by executing driverquery.exe
    • Installed Programs - Collected by executing reg.exe "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall"
    • System Information - Collected by executing systeminfo.exe
    • Current running process - Collected by executing tasklist.exe /SVC

Registry Changes

Adds the following registry key to run at startup:

  • HKCU\Software\Microsoft\Windows\CurrentVersion\Run\[Dropped_Filename]:
  • HKCU\Software\AppDataLow\Software\Microsoft\{GUID}\Vars
  • HKCU\Software\AppDataLow\Software\Microsoft\{GUID}\Files
  • HKCU\Software\AppDataLow\Software\Microsoft\{GUID}\Config

Network Activity

It connects to the following server:

  • bergesoma[.]com/images/[encryted_data]/[.jpeg|.gif|.bmp]
  • polinodara[.]com/images/[encryted_data]/[.jpeg|.gif|.bmp]

Where encrypted_data contains the Username, Compute Name, Version of Injected process, System IP address and malware specific configuration details.

Other Behavior

The malware also has the capability to:

  • Steal email data, which is collected by parsing different email file formats and applications (.wab, .pst)
  • Intercept the data and web-forms of the following browsers: Chrome, Internet explorer, Thunderbird, Firefox
  • Check for the presence of a virtual environment by checking the Device Informaton string against "vbox", "qemu", "vmware", "virtual hd"
  • Detect Phishwall software

Analysis on file: b3764e1a3d0f7d164436d565226800f3c06a58ec

Analysis by: Neeraj Singh

Date Created: -

Date Last Modified: -