Download the latest free virus definition files and update Bitdefender AV

Bitdefender Virus Definitions

Bitdefender Virus Definitions

  -  324 MB  -  Freeware
  • Latest Version

    Bitdefender Virus Definitions (64-bit) LATEST

  • Review by

    Michael Reynolds

  • Operating System

    Windows 7 64 / Windows 8 64 / Windows 10 64 / Windows 11

  • User Rating

    Click to vote
  • Author / Product

    BitDefender / External Link

  • Filename


With the Bitdefender Virus Definitions app, you can easily update Bitdefender (AV, IS, TS) on Windows computers when the Internet connection is too slow or when you don’t have Internet access. Desktop Products Updates for:
You can download the updates manually to a computer with Internet access and then transfer them to your offline computer using a removable device, such as a flash drive. The update package is called weekly.exe and is released every Friday. It includes all the virus definitions and scan engine updates that are available up to the release date.

The weekly.exe application is a Virus Definition Update only. If you are looking to install product updates, you must update Bitdefender using an Internet connection through the Update feature of the product.

To update Bitdefender offline using weekly.exe, follow the steps below:

1. Download the file corresponding to your Windows architecture and save it locally on your hard disk.

2. Double-click the downloaded file to start the setup wizard.

3. Click Next to begin the installation process.

4. Check I accept the terms in the License Agreement and click Next.

5. Click Install to begin installing.

6. Click Finish to close the installation wizard.

Bitdefender is a renowned cybersecurity company that develops a range of antivirus software products to protect computers and networks from malware threats. Virus definitions, also known as virus signatures or virus patterns, play a crucial role in the effectiveness of an antivirus program.

Virus definitions are essentially a set of codes and data that antivirus software uses to identify and detect known malware strains. These definitions contain specific patterns or characteristics that help antivirus programs recognize and categorize malicious software accurately. The patterns may include code snippets, file names, behavior patterns, and other attributes unique to different types of malware.

To effectively detect and neutralize new and emerging threats, Bitdefender regularly releases updates to its virus definitions. These updates, often referred to as virus definition updates or signature updates, contain information about the latest malware strains and their associated patterns. By keeping these definitions up to date, users can ensure that their Bitdefender antivirus program can identify and block the most recent and prevalent malware threats.

Bitdefender offers multiple ways to update virus definitions. One common method is through automatic updates, where the antivirus software connects to the internet and downloads the latest definitions in the background. Users can configure the frequency of these updates or set them to automatic mode to ensure real-time protection against new threats.

Additionally, Bitdefender may release manual updates for users who prefer to update their antivirus software offline or in specific scenarios. These updates can be downloaded from the Bitdefender website or obtained from other trusted sources.

The frequency of virus definition updates depends on various factors, including the severity and prevalence of new threats. Bitdefender aims to release updates as soon as possible to protect its users from the latest malware strains. The company's security experts constantly monitor the threat landscape, analyze new malware samples, and develop corresponding virus definitions to stay ahead of cyber threats.


In summary, Bitdefender's virus definitions are essential components of its antivirus software. Regular updates to these definitions ensure that users' systems are protected against the latest malware threats by providing accurate and up-to-date detection capabilities.